So I have been doing OPKs the last 2 cycles and I’ve just started again for this cycle. I’ve had it go up but never gotten a positive result on the strips and haven’t used digitals in about 7 months as they are pricey. This month if I don’t have a clear positive on the OPKs I want to go to my doctor and get the blood test done to see if I in fact ovulated or not…. My issue is it needs to be on day 21 on my cycle… which is a Sunday!! Can anyone tell me if that is a really strict rule or if I could get the blood test done the next day and it still be accurate? I don’t want to waste my time or money going to the doc to get it sorted if I can even do the blood test on the right day. Thanks I’m advance ladies ☺️