Pregnant before 6 weeks postpartum after loss?

I lost my baby May 13th she was born May 12 lived for a day and passed away due to negligence i feel even tho she was born at 23w 1 day. I got a positive pregnancy test. Has anyone gotten pregnant before the 6 weeks of having a baby? Or is it left over hormones. I did get blood work yesterday so just waiting for the results.