Okay , I'm 15 years old , me and my boyfriend are having sex , but we seem to be having some troubles , my vigina seems to be very small , and the condom got pulled off , we did't realize this until after her came , now the day after we had sex , I got an agonizing stomach ache , could I be pregnant ? I read that you can have some pain in your stomach within the first couple of days , I am very scared please help me ! And for the record I feel like a fool for asking .

Never feel foolish for asking questions, especially when it is something so important. You would be foolish to ignore the situation!

Most likely the soreness was from the recent sex or some other reason. You wouldn't be pregnant at that point if it were to happen as it usually takes a few days to get to and fertilize the egg and then at least a few days for the egg to implant into your uterus. To top it off, the timing of the sex would have to take place around the time your body is preparing to ovulate (release an egg), otherwise any sperm present would die off.

Could you become pregnant from the sex you had? Certainly... no time in the month is 100% safe. If this was very recent, within the last few days, you could see about obtaining something like plan b, or the morning after pill at the pharmacy. However, at 15 and depending on where you live, you may not be able to get it on your own.
Otherwise you will have to wait until your next period is due and see what happens.

In the meantime... either refrain from having sex until you are a bit older and would be better able to deal with a pregnancy and baby (which would be the ideal), or, if you are going to continue, consider another form of birth control along with the condom (which be sure is put on and removed correctly) to increase the odds of avoiding future worry about an unplanned pregnancy.