16 and possibly pregnant

I've been having sex for about the past month and a half now, with the same guy, and we've always used a condom. Up until about two weeks ago, he would always pull out before he came, even with the condom on, but then didn't do so once. I should've gotten my period 3 days ago, but still haven't had it yet. I've looked at signs of pregnancy, but am not showing many signs. I've noticed that my nipples and the area around them have been darkening, and i've occasionly felt sick to my stomach. The only other thing is i've had cramping here and there for the past few days as if i was going to have my period, and i've had some stomach pains in the middle of my stomach and on my right side. If I am pregnant, I have no idea what I'm giong to do about it. I'd really like someone to talk to, help me cope with everything.