Had unprotected sex 1/18-1-20

Got light period mostly brown blood 1/21-1/25

--- got on birth control pill 2/10 (doesnt become active until a full week so started working 2/17, period was due 2/16 and still is a no show.

I know I might sound crazy but is there any possible chance that i could be pregnant?

Im having some symptoms other than the late period like nausea, soar veiny breast and my nipples look darker. Idk if its me getting used to the bc pill or if these are possible pregnancy symptoms. I feel like im going crazy bc i wanna tell myself there is no possible way that you are pregnant but then why havent i gotton my period?