missed period?

i lost my virginity on the 15th of october (ik it’s weird i remember the day i just easily remember days like that) and i got my period about 5-6 days after but now i’m 8 days late on my period and not showing any signs of starting anytime soon. i also went to the hospital the 13th of this month for stomach pains and they did a pregnancy test and it showed up negative but i’m still stressing because i don’t know if a pregnancy would show up around that time and as of right now i’m terrified and i have no idea what to do.