OPK help please!

I got a blinking smile today but it wasn’t with my first pee because I forgot! It was about a half hour later but only a tiny trickle came out. Is it possible to get false positive reads on these? I am asking because I am still on my period (12th day now and super heavy). I should add that this is my first period following a miscarriage in September.I know this is not peak fertility but means I will ovulate soon correct? Can I still ovulate while bleeding this heavy? Doing the BD will be interesting 😳