Wondering if anyone out there has more knowledge than me about how these things work. I got some Clearblue OPKs, the ones that do the smiley faces, starting testing round about when it said to for my cycle length, BUT I didn't realise you have to use first morning urine so I did the very first test on an afternoon, late afternoon I think. Then after that, I did FMU each morning as it asked for. I got 2 days of the empty circle (including that first afternoon test), then 2 days of flashing smiley, and now this morning it's a static smiley. But did I mess up the test sensitivity by not using FMU for that first test? 🤔 Can I rely on these smileys being accurate? I don't have EWCM yet although it is wet (sorry, tmi).