Ovulation Prediction Kits – A Learning Experience

When you are trying to conceive you will notice exactly where you can find pregnancy tests in each store you go to. This is also true of ovulation prediction kits, or OPKs for short. But it's not just the stores where you see them; they seem to be everywhere today. The question of the moment is, do you know the proper way to use them?

The entire purpose of OPKs is that each day you test your urine to see if your body is preparing to ovulate so you can better time intercourse for conception. Sounds simple doesn't it; you purchase an OPK with between 5 and 9 tests and each morning around the middle of your cycle you test your urine. Right? Wrong! Worry not, for here we shall learn the correct way to effectively use an OPK. 

First things first, you need to know how long your cycle is. You will need to know how long both your shortest cycle and longest cycle has been for at least the past six months. If you don’t know, then use the 'average' cycle length of 28 days. Why does it matter how long your cycle is if you are going to use an OPK to detect ovulation? 

Knowing how short and long your cycle can be lets you know when you should start testing. Although the medical 'average' is 28 days, it is very normal for a woman's cycle to be as short as 24 days and as long as 36 days. The medical 'average' day for ovulation in a 28 day cycle is day 14, but that varies from day 10 (or earlier) for a 24 day cycle to as late as day 22 (or later) for a 36 day cycle. Because the LH surge that the OPK detects happens 24 to 36 hours before ovulation, you should start testing as early as day 5 for a 24 day cycle and as late as day 18 if you have a 36 day cycle. 

If you are not sure how long your cycle usually is, it is best to start testing on day 10 and continue testing until you have a positive OPK result. That is not the end of the 'when to test' lesson. Because the LH surge can last for as little as 10 hours or for as long as 30 hours, when and how often you test can be the difference between a waste of money and a wise investment. 

In order to be sure that you don't miss the LH surge, you should test twice a day. If it is possible, the tests should be done about 10 hours apart. However, if this is not possible, you can test in the morning between 6 am and 10 am and then again in the evening between 5 pm and 8 pm, and this should give you an accurate result.

So, now that you are ready to start using an OPK, how many should you buy? This goes back to how long or short your cycle is. You should expect however, to use at least 10 test strips for each cycle, figuring that by the 9^th or 10^th strip you will have detected your LH surge. If you know that you have longer cycles, between 30 and 36 days long, you will need more tests.

For a 24 to 28 day cycle, ten test strips should detect ovulation if you ovulate by day 15 and start testing on the morning of day 10 (the shorter your cycle, the earlier you need to start testing). If you have a 29 to 32 day cycle, twelve test strips is the minimum number of tests you should purchase, as you should start testing the morning of day 11. For a 33 to 36 day cycle, 14 test strips is the minimum you should have. Testing should be started on day 12, and continued until ovulation is detected. 

You noticed that I said 'minimum' quite a few times, and by this I mean that the fewest tests you should have on hand is that minimum number. You don’t want to find yourself needing to rush out at the last minute and purchase more tests because you did not have enough on hand and are having a longer than expected cycle. Here is a 'rule of thumb' to use when purchasing OPKs, always purchase at least six more tests than you think you will need.

So there you have it, when you should test, how often you should test, how many test strips you should have on hand, and why. By being educated about the proper way to use OPKs you are increasing your chances of them working for you the first or second month you put this knowledge to work. Many wishes for many positive results on your OPKs and your pregnancy tests!

About the author: Debbi Craig is the Suite UniversitySchool of Health Dean, the suite101.com Health Community Manager and is also the editor of the Infertility topic at suite101.com. Debbi has been doing research and writing about preconception and infertility issues for five years and continues to expand her knowledge and understanding in these, and many other areas. Because of Debbi's research and work with a support group, several women have used her information to achieve pregnancies they never thought possible.

Debbi's most recent Suite University course Creating an Online Support Group will guide students through the process of creating a self-help support group that benefits not only the group owner, but also all of the group's members. This course also informs the student of what to look for in a good online support group so they can find not only the support they need, but also information and friendship with others that understand what they are dealing with.