15 and might be pregnant..HELP

Last Friday on the 10th I had sex for the first time. It was unplanned and unprotected. I was dumb and didn't realize the repercussions of it. Today is the 18th...the day I'm supposed to start and I didn't. I'll be taking a pregnancy test ASAP. But what if i am pregnant, I'm 15 I can't have a baby. What do I do??