How long will period last on loestrin 24????!!!! I need to know?

i started my birth control last month and instead of taking the placebo pills i started the new pack. I thought i skipped my period because i didn't. and a week later, i'm on my period now. so i was just wondering how will the period last including the light days. i started today and it's pretty light. i usually bleed heavily on the first day before i got on BC but it's not that heavy.