pregnant

i’m 15 and i think i’m pregnant. i had sex on the 13th and i was supposed to get my period 3 days later. i didnt think anything of it and 2 weeks passed when i realized i never started and i felt absolutely horrible. i told my family a week ago and got a test and one had a VERY faint line and the other was negative. every day i’ve gotten more and more symptoms. what do you guys think?