So ever since I first got my period four years ago I have experienced a pattern of having it regularly and very heavy for about six months, then not having it for six months. Last year I experienced this around this time of year and was scared of pregnancy, so my mom took me to a doctor to get an exam when I had to confess my worries and be tested. The doctor confirmed I was fine, and I started having regular periods after the pelvic exam. I didn't have sex again until two months ago when I fell in love, but I had my period since. We used protection except for two weeks ago, though we did not "finish", and I have yet to have my period. I do not feel different other than that, and I experienced my usual bloating and cramps before the fourth, when I usually get it... I took a test on the seventh and eigghth, both came back strongly negative... My assumption is I'm not, but the chances scare the hell out of me! Does anyone think they know? Oh, I must add that I have recently dealt with stressful events, another possible explanation.
I wish I had thirty hands so I could count all the times in high school when I had girls tell me they thought they might be pregnant (giggety, giggety, alright!)...and I am currently childless as far as I know. I'm no M.D. but I'd say if he didn't come in you and you are getting negative test results two weeks or more later - you are probably just worrying needlessly but let it be a lesson learned! Not everyone is as skilled at the pull and pray as myself (ok, but seriously contraceptives are made for a reason).
I think you need to read Taking charge of your Fertility by Toni Weschler. You might be, but probably aren't. And the more you know about your body's signs of fertility, the less stressed you'll be about the possibility.