Temp spike and darkening OPK on day three of period?

Anyone insight appreciated. I’m on day three of my period (hardly any spotting today). I’ve been feeling little off the last two days during my period but have had zero cramping or anything. My bbt spiked this am from 97.05 yesterday (normal pre O temp) to 97.70 today(normal post O temp) so I used an opk. I normally don’t use them till at least day 12. It’s not positive but definitely way darker than it usually is before ovulation. I know there’s no way I could already be ovulating-I’m only on cycle day 3 and no way I could be pregnant since I’ve been bleeding the last three days. Anyone experience anything like this? I am 35 so could just be hormones getting weird. Thanks!