Confused with my body

Okay so i got my birth control taken out on October 30 and i finally stopped bleeding on November 8th now idk if that was my period or not because i have been bleeding alot with the nexplanon anyways the bleeding stopped and i had unprotected sex with my boyfriend on the 8th and the 21st i took a pregnancy test on the 23rd and it was negative but my period is still late ik im not pregnant but idk what's going on also my nipples are sore rn