I did a stupid thing

So my boyfriend and I have LOTS of unprotected sex because we ran out of condoms and we're both broke college kids sleeping on a friends floor currently but we do use the pullout method. He's never finished inside of me but I've been having symptoms and we definitely we're going at it like rabbits while I was ovulating because I didn't get this app until afterwards. Im very new to regular sex even though it's been two years since I lost my virginity and I feel incredibly irresponsible. I have about nine days left until im supposed to start my period so I can't take a test, what are some warning signs to be looking for this early?