Positive hpt 1 month after miscarriage

I'm trying not to get too excited, I feel like the same thing will happen again. Has anyone had a similar situation? Also a friend of mine made a comment that has me a bit worried- she was surprised my uterine lining had enough time to properly prep for a baby... Is this a thing I should be concerned about? I have read on here that some people are given the advice to wait a month offer a MC but I was not told this by my doctor.