Fist of all u need to take a pregnancy test so that you know for sure, there is no point getting yourself worked up about it if ur not, also the more you worry about it the longer it wi,l take you to come on if your not pregnant.
If you are then some advice of what i did when i was in your exact same position, being seen as the good girl can be hard to break the news, but u have first got to tell the father of the baby, then u should tell the member of ur family which u can talk to most and isnt going to completely freak out, they can hopefully help you to tell the rest of your family. I hope this helps you. Good luck.