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Ovulation Testing: How Ovulation Predictor Kits Work

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Ovulation Tests - or Ovulation Predictor Kits (OPKs) - allow you to predict, with great accuracy, your most fertile time of the month. Easy to use, ovulation predictor kits can greatly increase your chances of becoming pregnant. To improve ovulation testing results, visit our Ovulation Test FAQ for testing tips. For more information on Ovulation and your Menstrual Cycle, click here.

Using Ovulation Tests to Predict Fertility

Ovulation is the defined as the separation of a mature ovum from the ovary after a follicle has been formed.

For many women, ovulation takes place midcycle, around cycle day 14. Of course, irregular cycles and countless other factors can contribute to ovulation taking place either earlier or later. That's why we use ovulation tests and chart fertility. In fact, "normal ovulation" can occur as early as day 8 or as late as three weeks into your cycle. When ovulation occurs is a coefficient of menstrual cycle length, so women with long cycles will ovulate later than women with shorter cycles.

To provide a brief overview of ovulation, the growth of an ovum takes place due to the influence of FSH - or follicle stimulating hormone. At ovulation, a surge in lh - or luteinizing hormone - facilitates the separation of egg from follicle. Here, cilia at the end of the fallopian tube move over and brush the ovary to help assist in the release of egg from follicle. For more on how an ovulation test allows you to predict this period of peak fertility, read on!

> How do OPKs work?
> How do I interpret ovulation test results?
> How do I determine when to begin testing?
> Ovulation Testing FAQ
> Fertility Monitor FAQ
> Capturing the Surge: Advanced OPK Suggestions!

Ovulation tests - or ovulation predictor kits (OPKs) - are excellent tools for predicting ovulation, a woman's most fertile time during her menstrual cycle. Unlike BBT charting, ovulation tests anticipate ovulation - not just confirm that ovulation has taken place. Visit Early-Pregnancy-Tests.com to see a photo gallery of positive ovulation test results.

Ovulation tests work by detecting luteinizing hormone (LH). Just preceding ovulation, women experience an "LH surge" - a sudden, dramatic, and brief rise in the level of luteinizing hormone. Ovulation tests detect the LH surge, allowing you to accurately predict when you will ovulate. A positive result on an ovulation test means that the woman will most likely become fertile over the next three days - with peak fertility at 36 hours following the LH surge.

How do OPKs Work? Luteinizing Hormone and Ovulation
How do ovulation tests work? At the beginning of the menstrual cycle, the body begins to produce follicle stimulating hormone (FSH). FSH facilitates the formation of a follicle on one of the ovaries. The follicle contains and nurtures the egg. When a follicle has adequately matured, a surge of Luteinizing Hormone (LH) causes the follicle to burst and release the egg into the fallopian tube - the moment of ovulation.

Throughout the menstrual cycle, a small amount of LH is produced - but during the middle of the cycle LH briefly and dramatically increases. Elevated quantities of luteinizing hormone facilitate ovulation - and OPKs detect this LH surge through anti-LH antibodies contained in the sensitive testing membrane of the test.

The LH surge is, alas, very brief - and in order to detect the LH surge, a woman needs to test at the right time of the month - and the right time of day. As LH is produced by the body in the morning, mid-afternoon is considered the ideal time to test.

Once the LH surge has been detected, successful fertilization is most likely to take place one to three days following the LH surge - with peak fertility at 36 hours post-LH surge. Since this ovulation "window" only opens once per month (and the unfertilized egg has a short 24-hour life-span) predicting ovulation accurately is very helpful when trying to become pregnant. Below, you will find information on getting the most out of your ovulation tests (and visit our Ovulation Test FAQ for more testing tips).

Using OPKs and Interpreting Ovulation Test Results

Ovulation tests come in two formats: test strips and midstream tests. To use the ovulation test strip, you fill a container with urine and hold the test strip in the container for several seconds. With midstream tests, you hold the test in your stream of urine. Both test formats are equally reliable. Always read ovulation test kit instructions carefully.

With most home ovulation testing products, the "reaction time" of the test is five minutes. At five minutes, you can interpret the tests. All tests have a "control" color band (or color line) that indicates whether the test is working or not. Also, the control band provides a color/intensity baseline by which to interpret the "test" band results. The "test" color band indicates a positive or negative result (please refer to the graphic below).

A positive result (indicating an LH Surge) is indicated by a test band that is of equal or greater intensity (equal or darker) than the control band. A negative result for the LH Surge is indicated when the test band is of lesser intensity (lighter) than the control band or cannot be seen. A negative result means the LH level of the urine sample is at or near its normal level and that the LH surge is not in progress. Remember, there is always some quantity of LH in your system, so a light color band in the test region is NOT an indicator of a positive result. 

How do I Determine when to Begin Testing?

To determine when to start testing, you must first do a little calculating. Use the Cycle Chart below to figure out when to begin testing for your LH surge.

First, determine the average length of your menstrual cycle. The length of the menstrual cycle is the number of days from the first day of menstrual bleeding to the day before bleeding begins on the next period. Determine the usual length of the menstrual cycle over the last few months. Then, refer to the Cycle Chart to determine on which day of the menstrual cycle to begin testing.

Your Cycle Length

Day to Begin Testing

21 days Day 5
22 days Day 6
23 days Day 7
24 days Day 8
25 days Day 9
26 days Day 10
27 days Day 11
28 days Day 12
29 days Day 13
30 days Day 14
31 days Day 15
32 days Day 16
33 days Day 17
34 days Day 18
35 days Day 19
36 days Day 20
37 days Day 21
38 days Day 22
39 days Day 23

 Read More About:

> Ovulation Test FAQ: Testing Tips and Tricks
> Pregnancy Testing
> Ovulation and your Menstrual Cycle
> Ovulation FAQ
> Clomid and Ovulation Tests
> Saliva Based Ovulation Predictors

. Ovulation Tests Instructions
> Ovulation Test Strips
> Ovulation Midstream Tests

Comments

Hi! I am 41 and got married late in life. I was married 1 day before my 39th birthday. We got married in October of 2007 and became pregnant for the first and only time in January of 2009. Unfortunately, I miscarried in March. Well, recently we bought an opk and started using it on day 9. I am currently on day 16. I find these things hard to read. It appears that it could either be pos or neg, I'm not sure. I will have my dh look at it when he gets home. He is better reading these things than I. At any rate curiously enough I took my temp on day 15 and it was much higher than it was this morning. We made love last night. I also had a lot of mucus today, but it very well could've been semen. I will observe it again later. We have been trying to get pregnant again for about a year or so. Are these opk's hard to read for others and is my age making it harder for me to conceive a second time around?

mvplady - Feb 02, 2010
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gwaeg - Jan 29, 2010
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hi..iam 24 years old and had my first child when i was 17..ans it was by c -section...every since then my periods have been crazy...well the problem is...that i ave been on xanax for 2 years now and my periods are longer apart now..any where from 31 to 39 days apart..some time they are so light that i just have to have a panty liner..so anyway..it's 1-4-2010..and i didnt get my period for december....and i have tooken 2 preg. test both neg....i keep cramping..like iam going to start..but nothing..and all so...i hope this is not to much info..but i have that thick clear discharge..like iam ovulating..so i dont know what is going on...any advice would help...please..thanks for any one that helps

Anonymous - Jan 03, 2010
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i havent had regualr period all my life how am i supposed to know how long my cycle is and all that when i can go two years without a freakin period any help would be greatly appreiated. sandra

athenus - Dec 29, 2009
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i have a 28 day cycle, and i have been taking a clearblue fertility test and it keeps coming up negative! i started my period on the 23rd so i should be ovulating around the 6th/7th, and nothing yet!!! can someone help me? can people ovulate late?

Anonymous - Dec 07, 2009
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The easy digital tests are extremely expensive.. But the first suggestion provided here is very helpful.. To use clearblue tests. I have the Cvs kit. Well, it might be simple for many. For some reason I am always confused when I need to interpret the results. After 5min it's right to check the test line.. That's when my tests have been negative till now.. (35 cycle .. Today is 15th) but when I chk the strip may be after an hour it gets darker.. Uff am tired.. I guess the test is rendered useless after 5min from dipping it in the sample. Good luck everybody!!!

Pelican - Nov 29, 2009
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I have read several posts on the lines of a OPK being hard to decipher. I would suggest a digital test. Clear Blue Easy has a digital test that gives either a circle for negative or a smiley face for positive. Hard to mess that up!!

Anonymous - Oct 14, 2009
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I have been trying for a baby for months now, but nothing seems to be happening. I know sometimes it takes longer to concieve, but I want to know if these tests will work cos I have never tried one before.

Anonymous - Oct 12, 2009
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i had a miscarraige in january and then i had to terminate another pregnancy in july i was always had a 28 day cycle but my last two periods have been 43 and 30 days i am trying to conceive again how do i predict my ovulation date now

Anonymous - Oct 06, 2009
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First Day of Last Period:
Cycle Length:
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Luteal Phase Length:
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Ovulation:
Due Date:
Fetal Age:

Note that you are most likely to get pregnant if you time your lovemaking to occur on the days right before - and on - your ovulation date. Keep in mind that the projected ovulation date above is simply a “best guess” estimate based on your cycle date information. The most accurate way to pinpoint your most fertile time is through the use of urine-based ovulation tests or with a fertility monitor. We have partnered with Early-Pregnancy-Tests.com, the Internet’s leading supplier of preconception products since 2001, to offer low-cost, FDA-approved pregnancy and ovulation tests – with free same-day shipping.

 

Now that you’ve calculated your ovulation date using our ovulation calculator, we have a number of other helpful tools you can use to help increase your chances of conceiving.

 

  • Create your own personalized ovulation calendar! You can even provide an email address so that you receive email alerts of your most fertile days, when you can begin testing for pregnancy, and more.
     

  • Create your own personalized fertility chart! This is a highly accurate way to pinpoint your ovulation date that relies primarily on basal temperature charting. (Visit Early-Pregnancy-Tests.com for an accurate, inexpensive basal thermometer.)
     

  • Connect with others at our online community! If you have questions about trying-to-conceive – or if you just want to vent a bit – we have a wonderful, vibrant community of people who’d just love to hear from you.

Find your most fertile time.
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