Alas, now you don't need to post and ask whether or not you're pregnant. Instead, you can take this quiz at the super-informative and super-helpful website, SexualityandU.ca. cool
Keep in mind it can't actually tell you if you're pregnant. It just tells you what your chances of being pregnant are.
The only way to know 100% for sure if you're pregnant is to take a pregnancy test and then see your doctor. But, if you're worried about potentially being pregnant, then this quiz might help calm some of your worries or answer some of your questions. 3nodding
[Because this is just a link, I'm not including this in the official sticky list.]
The Teen Sex, Pregnancy and Puberty Guild
A guild for teenagers covering topics centering around teen sex, pregnancy, puberty, and other aspects of teen life.