Period for 3 weeks on metformin?

Hey, not sure if I picked the right flair so let me know

I have mirena IUD that controls a lot of my period symptoms by simply preventing them. Recently, I started metformin to try to help some of the insulin resistance.

I started on June 1st and had a period (light to medium flow) for the first time since February. It lasted for 3 weeks. My doctor (gp/pcp) never heard of that happening with metformin but figures it was my hormones figuring out a new normal.

Now 12 days have passed and I got my period again.

Has anyone else experienced this when they started metformin? Did it level out after a while of consistent use?

Thanks in advance ☺️