First postpartum period on hiatus?

I am almost 12 weeks pp and I've had friends who were pregnant around the time I was whom have started their periods start back up. I had a little spotting which started brown then went pink for a few days then stopped. I thought for sure I was gonna start my period but now nothing. Starting to get worried that I'm one of those people who get pregnant before first pp period. Not breastfeeding, haven't been in about 2 months. When did your first pp period start?