2 periods???

So I started my first period after being pp for a year and a half on the 22nd of aug. It ended the 26th and now today on the 4th of sep im bleeding again.

I took a pregnacy test a week before my period, after my period and yesterday. They all came out negative. I'll be re testing in 2 days just to make sure I'm not pregnant.

I was diagnosed with having a heart shaped uterus and Adenomyosis im not sure if these are just side affects from having these things, and I've asked my dr about them but never gave me clear answers.

Has anyone experienced this?