Being a Virgin is no protection - where blood can come out so sperm can swim in. If semen got into your vulva and you failed to wipe it out, there would be a slight cause for concern. The way you describe it this did not happen, so I think you are safe. It’s time to buy some condoms of your own and insist on their use when you are naked together.
if you don't remember wiping you vagina you should take a pregnancy test just incase and you should drink lots of water