metformin for PCOS

Danielle
I haven't had a period since December of 2015, I've been on metformin for a few months and finally got a period on December 3, I'm still bleeding. It's slowed down a lot but still there.
I took metformin three years ago for my first pregnancy and didn't have this reaction. It gave me a normal 6/7 day flow every 30 days.
Has anyone had an initial long period after not having one for a while? Thanks!