Unprotected sex... Help !?!

I had unprotected sex Saturday for a minimum of three minutes then stopped and he didn't finish in me. Then Sunday I had unprotected sex twice but he didn't cum inside me I know for a fact and he is almost positive he pre-came before he entered the vagina. My period tracker says I was ovulating and I'm freaking out... should I take plan b or so it's said it doesn't work after ovulation day?! Helppppp.