How much blood is TOO much?

I am just finishing up my first pack of birth control. I also have pcos. I got my period and it is really heavy. I soaked completely thru a size 5 overnight pad thru my underwear and pants onto my bed sheets. During the day I am soaking thru a super plus tampon every hour and a half. It’s also pretty painful with clots which I know is Normal but I feel like I need to add that. I’m 18 so I know I’m going to sound stupid because I’m sure this is normal.