Birth Control, lots of bleeding, need help

Alyssa

I'm taking the pill and it was prescribed by my high school and the first month my period lasted 18 days the next period was on time but this is the 3rd month and now i had my period 2 weeks after my last one and its lasted 10 days, ive also been getting sick a lot.. Is that right or should i stop taking them? My mom said that it's not good and i shouldn't go through the school, but its free and we dont have much money... what should i do?