am i pregnant?

my predicted period is supposed to start next week. i had sex for the first time about 2 weeks ago and i don’t know what the signs of pregnancy are. i’ve been bloated all day today and i’ve had nausea for a long time (even before i’ve had sex). i’m only 15 and i really don’t want to be pregnant. i had sex again but it wasn’t like for long. he didn’t cum until his dick was outside of my vagina. should i be worried?