first time on birth control, confused about period

hi all! i started birth control around three weeks ago (currently on my fourth week, i just started taking the placebos) and i wasn’t fully informed on how it could alter my period but now i’m sort of worried. i’m not sure if age matters in terms of the severity of side effects/impact on menstruation. my periods usually last 6-7 days but i’m currently on my 9th day and i don’t see it stopping any time soon. for the first week i had very minimal bleeding (i wore panty liners instead of pads) but since last night i have extremely heavy bleeding. also, i used to cramp only on the first day but now i’ve been cramping every single day. i just wanted to ask if all of this was normal? i tried using google but nothing turns up. no one in my family has ever been on birth control either so i have no one else to ask