Please read, confused.

Sorry in advance, but you guys always seem to be so helpful. I had a miscarriage in july, and after a few awful months, conceived my 🌈 baby. Using OPKs, I'm pretty sure my surge was 10/29. So I have had some light cramping so far, is that normal in early pregnancy? Also, yesterday which would have been around i guess around 16-17 days past ovulation, i had a single drop of brown blood in my underwear. Is that implantation bleeding? Or is it too late for that? After that, I had some light to mild cramping. Please help I'm freaking out. Did anyone have cramping during the first couple weeks? Also does anyone know what #dayPO the had Implantation bleeding?