Can It still happen

Victori

I had my period July 16-18th. The 18th was just a little spotting. I had sex on the 18th, I took a opk yesterday and it was almost positive. i took one today and it was lighter than yesterday. Could i have already ovulated? & could I have ovulated when i was on my period?. I’m just curious if i could get pregnant if I ovulated during my period.