HELP! Help! Help!

I was with my boyfriend 3 times last week l. I was not fertile though. Yesterday was my first actual fertile day but last time we were together was, Saturday night. My stomach has been hurting, I get some cramps, sharp side pains, I feel like I want to throw up but I don't. I'm 19 years old and people have told me at this age, it is possible. It's been one week though. Can I be pregnant?