How common are false positives really?

We’ve been trying for almost 2 years 😔

About 4 months ago, I got a false positive on a Walgreens early response. I later read about how they are notorious for that, so I switched to FRERs.

A month ago, on a FRER, the top 1/8th of the line was obviously a faintish pink, and if I squinted real hard it looked like the rest of the line was there, but the others in the same pack were all BFNs. I read about it and apparently it has happened to other people.

Well today I’ve been feeling very mildly nauseous off and on, and my boobs are sore, so I grabbed another FRER, thinking “I can’t get THREE bad batches, right?”

Well guess what...the top of the line is there again. Its MUCH fainter this time, but I feel like I can see the bottom of the line easier than I did last time. So maybe? But I don’t want to get my hopes up like last time.

But now I’m wondering - if I have had 3 bad batches...how freaking common is this??