Period while breastfeeding

Destinee • Alayna Rae 10/26/15 @ 7lbs 5.9oz Follow us on our amazing journey as we raise our daughter with much love💖
I've heard that if you exclusively breastfeed your period won't return for 3-12 months or something like that. Well My daughter was only 6 weeks when my period started again.. Is this normal? I exclusively breastfeed her. When did Mother Nature return for you breastfeeding  ladies after birth?