I am 20 yrs old and the guy i'm dating is 21. Me and the guy i'm dating had sex for the first time on october 8th after we had partied all night. After that we didn't see each other for a week before we did it again. Well on october 17th I started what I think was my period, but it lasted only 3 days instead of the usuall 5 or 6 and was lighter than normal. It wasn't super light anything but it was definitely lighter. Everytime we've had sex it was unprotected but he he used the pull out method. Is it possile that I could be pregnant?