I see this question pop up on the boards regularly, so I thought I would share my experience and let you know more about my postpartum period than you ever wanted to know.
There is a big range for when your period can return, but a poll on the boards amongst exclusively breastfeeding mamas showed that most people got their period between 6-9 months or 12 months+ postpartum. Everyone is different of course, but I think whether you’re exclusively breastfeeding, your little one is sleeping through the night or eating solids/nursing less can have an impact on when your first period returns postpartum.
Charlie had been sleeping through the night since 4 1/2 months and shortly thereafter I stopped waking up in the middle of the night to pump. I was pumping 4-5 times a day and stopped exclusively pumping when he was 9 months old; my period returned two months after that. Honestly the details of my first postpartum period are a little hazy because it was 4 years ago, and I got pregnant with Olive quickly after my first two postpartum periods. But I do remember it being much heavier than normal.