Your thoughts on ovulation predictory kits (OPKs)

[Atia_Julii]

I always thought these were totally reliable.  I always buy the Answer brand because I get 20 sticks for a decent price.  So, this month, I'm on a fertility drug, so I've had constant ultrasound monitoring as well as using OPKs.

This past Sunday, I received a positive on the OPK and that was a day I was also scheduled to have an ultrasound done.  The nurse did my ultrasound, and said there was no way I could have gotten a positive because my largest follicle was only 15 mm.  Okay. . .

So today I had another ultrasound, and my largest follicle as 24 mm, and I had a blood test done that confirmed an LH surge.  I decided to test myself as well this afternoon, and although two lines came up on the test, one was definitely darker than the other, which is a negative.

I'm just wondering if I've had faulty results the entire time I've been TTC?  I would have never known had I not been having ultrasound monitoring.  I would have been BDing like crazy last Sunday, and would have completely missed my ovulation!

Has anyone else experienced something like this?

[Atia_Julii]

I was on Letrazole (Femara) for the first few days of my cycle.  My RE was surprised I had a positive as well.  He didn't mention that Letrazole would give a false positive.

[Latrice414]

Fertility drugs will give you false positives, i dont recommend you use them if your on drugs, but if you do there are certain peramaters for when you should use the opks after stopping the drug.

What drugs are you on?