I'm 9 weeks pregnant and using progesterone as doctor told me too. can i keep breastfeeding my 11 month old baby girl ?

Yes.: I imagine you are taking something like prometeium, to prevent luteal phase defect., it is safe for your nursing child but may affect how much milk you produce. Good luck with the pregnancy!

Insure nutrition: Yes, but make sure you're getting adequate nutrition to cover all your losses, both to your pregnancy and your breastfeeding. Check with your OB and a good registered dietitian.

Don't stop!: Long-term benefits of breastfeeding a baby are huge, and a mom will be able to breast-feed both after delivery with no problems. Absolutely no risks associated with continuing to breast-feed during a new pregnancy. http://www.babycenter.com/404_is-it-safe-to-breastfeed-during-pregnancy_8935.bc