Could I be?

Hey guys.... Okay so me and my boyfriend had sex the last day of my period last month which was on the 24th and we also had sex the day after that, both time cumming inside me. I know sperm stays inside the body for 5 days or something like that however last week I started feeling weird cramping that resembled menstrual cramping. I want to know am I over thinking or could I be pregnant and when should I test.