constipation and periods?

it’s a gross topic, but...

recently when i get my periods, i’ve been getting super constipated about a week before and during. sometimes it’s so bad that i can’t sleep and it hurts to the point where i need pain killers. a lot of times i get super bloated because of this as well.

help? i’m drinking enough water and everything is the same as before. i’m really confused as to why now i’m like this.