Missed period!!

Ok so I’m 17 I just started taking birth control n the middle of the month as my doctor told me (the 18th) I was supposed to start my period about two days ago I am late I am 100% not pregnant and I have cramps but no blood just weird heavy heavy heavy discharge .ive never had this much and it’s weird also this birth control has made my period acne even more noticeable I hate it