Newborn Breastfed baby won't poop... I need help

Any mom's who breast fed please read: MarcyJo is 12 days old and has only had one assisted poop almost a week ago other than her intitial dark tarry poop.. the Dr said if she hasn't pooped on her own in 7 days.. which is Monday to contact him so we can look further into this to be sure she is getting enough milk and or there isn't any intestinal blockages or other things going on... Has anyone else experienced this with a breastfed newborn? If so please let me know your experience. I am getting more and more worried about her everyday that passes without a poop.