Hospital leaving my network? Help!

Starlight • Expecting a miracle baby after a long road!
Question for other Americans (or people who understand our mess of a healthcare system):
My husband and I have our insurance through the Health Insurance Marketplace, because we work for small non-profits that can't offer group insurance. I just found out that a big group of hospitals in my area will no longer be in my HMO network in January! The only 2 places my doctor has privileges at will be gone...including the one I have already registered with, toured, and started paying for delivery! 😫 No PPOs or other options are on the marketplace in my area, so there's no other option that would include my doctor and hospital. We've looked into medishare programs, but the won't cover maternity unless you joined before you conceived. 
Do you think it is possible that my insurance would extend my current coverage one more month? Can they realistically cover a hospital leaving their network? I have a high-risk pregnancy and doubt I will be able to find a good OB who takes my insurance and delivers at the public hospital this late in the game. I hope someone else has gone through something similar and can give me some advice for talking to my insurance and doctor!