So i lost my virginity last weekend. i started birth control two weeks prior to that. i started birth control as soon as i was prescribed it not right after my period and my period has been irregular for the past few months (why i started birth control). but after i had sex i experienced bleeding which i thought was normal, and spotting for a few days. then i ended up getting my period after that, in the middle of my week 3 pills. should i be worried? is it the birth control regulating itself? bc my periods used to be 19 days apart and around the time i had sex i was at about 21 days from my last one