Birth Control

Hey girls
I've been on birth control since December-ish but there was about 15 days where I wasn't taking the birth control. During the time where I wasn't on the pill, me and my boyfriend had unprotected sex and he did cum in me. I peed after (I know that this isn't an effective method for pregnancy protection). I have been stressed lately ( I even found my first grey hairšŸ˜­) so idk if this is playing a factor in my period being late now.
My period is 6 days late now and I did take a pregnancy test about a week ago but it came out negative. Is it possible that stress and the birth control could have made my period this late or am I most likely pregnant?
I would really appreciate hearing everyone's feedback and experiences!!