the pill

okay so my period's horridity was inherited from my mother who had it so bad that she started the pill at 15 to make her periods a little easier. i was cursed with this same issue. like it's actually awful how much i bleed and how badly it hurts. regardless, she really wants me to start the pill but i've been antsy about it and am not sure why. just the idea scares me. so can anyone explain physiologically what's going on in my body when i start the pill and why it's a good idea to start given my circumstance? thanks!