Someone help me😪

I had sex on Valentine’s Day with my ex because my boyfriend and I broke up 5 months ago, a few days after I made that mistake we decided to work out things 🤦‍♀️ and we ended up having sex on the 23rd and 24th and now I’m pregnant. I have a 30 day cycle and my period comes the 7th or 10th of every month can I tell who’s the father without a paternity test?