7 weeks pp question.

When I gave birth to my daughter my doctor was surprised how little I bled. I didn't go through pads or have any clots and after a week the bleeding quit. Around 3 weeks my husband and I had unprotected sex, we used the pull out method *so dumb I know!*. Well around 6 weeks I had light pink spotting that only showed on toilet paper, then the next day it turned light brown and now nothing. I've been cramping ever since. What could this be? Start of af or ? I'm breastfeeding but only twice a day due to low supply, and I just started the mini pill.