Pregnant?

Ok so my bf and I got a little frisky during a make out and he slipped in just the tip of his dick but then it started to slowly slide in further (this lasted probably only 2 mins till his brother came home..) this happened near the end of my period (I had a tampon in me) and he was no where near cumming and he doesn't get precum. Im worried now bc me period is late by 4 days...could I get pregnant from that..?