Period confusion

Hi so this is my first time posting here but im a bit confused and nervous/scared rn, My periods have been regular for a long while and recently i was suposed to start my period on the 24th of november, that day all i got was spotting, the days after no blood at all. The only real recent change has been my boyfriend has recently move in with me in the begining of the month so ive been havimg sex more often than before, we do use protection and i am on birth control tho. I just need some advice on what this could possibly mean, since my calender says i should still be on my period but ive still had no blood other than the first day of spotting. Sorry for this post being so long but thank you for any help or advice.