2 heavy periods a month?

Has anyone else had 2 periods a month? This is new for me. I have an appointment with my gynecologist in a week but this is stressing me out.

The one I'm on now, number 2, is also now going on day number 10. My periods are usually 5 days long max. They are also exceptionally heavy. I had to switch from tampons to a diva cup and I have been bleeding out of the diva cup by mid afternoon even though I get a good seal.

I just had standards labs drawn by my PCP as well as thyroid labs and everything came back normal.

This is month 3 that this has happened, but this is the longest period by far. No chance of ppregnancy, I am on year 8 of the Mirena IUD.