I've been using OPKs for the first time this cycle. I've already gone through an entire box without getting a positive. I just realized today that I wasn't supposed to use FMU. DAMN! What time of day should I test?
Welcome to the world of mid-cycle peesticks! Some manufacturers claim that using FMU can cause false positives due to the urine being too concentrated... but in my personal experience I believe FMU is more likely to cause false negatives.
For you, my lovely citizens of Peestick Paradise, I recently did a little experiment. I tested using OPKs both with FMU, SMU, 3 pm and 8 pm. Here's what I got...
Of course, your results may vary. In fact, MY results may vary from cycle to cycle. But I've tested with OPKs using FMU before and have never gotten a positive. I believe this is because LH surges (typically) later in the day.
Different women find testing at different times works better. Just after noon, however, is a pretty common time to have success. Be consistent so you can see a pattern in your peesticks, if there is one. Some women notice the OPKs get darker and darker until they get a positive. This gives them a bit more advance notice of there impending fertility. For others, there is more variation and no real pattern.
You may want to consider getting IC (internet cheapies) OPKs. The store brand ones are very expensive and it can certainly add up. You can buy ICs from Babyhopes, Ebay, Amazon and various other outlets. I also sell them (through babyhopes and amazon) at the ttc store (look under ovulation tests). Some women do better with different brands of tests.
It is possible you missed your surge this cycle due to using FMU. It's up to you if you'd want to invest in more OPKs for this cycle or not. If you had other fertility signs, and you are well past your usual ovulation date, you may want to just write off OPKs this cycle and start fresh next cycle. (Of course, hopefully you caught the egg and there won't be a next cycle for a long time!)
Good luck!
