Work and periods?

I’m only 17 so this is the first time I’ve had to work while on my period. I have the copper IUD and my periods are extremely heavy and I get horrible cramps. I work 8-9 hour days 5-7 days in a row

Im really worried about working while on my period because I bleed through a regular tampon in about 2 and a half hours and nothing helps with my cramps. I’ve tried everything. Do you guys have any tips?