First month on Birth Control and really bad period..

Li
So this is my first month on Birth Control(Pill) I was previously on it about two years ago for a month.. Around my ovulation day me and my SO had a accident where he accidentally ejqculated onto the opening on my vagina.. I realized I should be on birth control and got a prescription! I started taking my birth control a few days into my cycle.. I got my period yesterday and I never had a period so bad.. TMI but I even bled through my underwear and I have heavy flow and long pads!! I even had upper stomach cramps and I don't know if Its Birth Control causing this!