Breastfeeding and Period

Sherise • 2 of my own...2 of his own...baby number 1 for us! #superexcited
I'm 7 months post partum and I'm in shock! I am exclusively breastfeeding at home. When I'm at work I pump so baby can have breast milk through a bottle while at daycare. This past week, I started a period. Full on heavy period! I thought I wasn't supposed to get a period until I stop breastfeeding. What's up with that? Any ideas/takes on what is going on?