Assessing Pregnancy Risk After Unprotected Sex

Question
I'm a little worried that it might be possible I'm pregnant.Im not sure if your even the right person to ask. But I figured its worth a shot.So,Im 21 years old. I've never been on any kind of birth control. My boyfriend and I had unprotected sex today. I gave him a blowjob and he came, then we had sex for like a minute before he had to pull out. and then after that we went back to doing it. I know the "pullout method" is stupid..  I looked at a ovulation calendar and according to that I'm ovulating today.. a little earlier tonight I started cramping on one side, so I guess the calendar was right. I know that only time will tell. But in your opinion,being I had unprotected sex while I'm ovulating.. is it likely that I'm pregnant or do I most likely have nothing to worry about?  Thanks

Answer
Assuming that you are ovulating, if he had fully ejaculated inside, you'd have about 25% chance of getting pregnant.  Since he came before intercourse, and then pulled out, I think pregnancy is fairly unlikely.  However, it's still possible.  You might want to consider Plan B if you really don't want to get pregnant.  It also sounds like you would be well off to find some good method of birth control for the future.