I am having symptoms but not sure if i am preg.

I am 13. I had un protected sex on friday…. adn then on saturday i was really sick… and then on monday which was yesturday …. [only 3 days later] I was vomitting at night…and that never has happend to me..and then today my stomache was hurting at my lower abdomen. Please help me here….. Im really scared…. 🙁 :unsure: :S