My case is my visa will expire on Dec 23 2015. I got pregnant and my due date is january 9 2016. I am already 34 weeks in my pregnancy. Can I still travel by plane for 20 hours to get home to my home country from here in norway? If not then it is possible I will be overstaying until I give birth. How much is the fine for this? Will I get deported? And how long is the ban from Norway? Or I am also be banned in the rest of the shengen countries for overstaying here in norway? I hope somebody could answer.
Assuming the child has now been born in Norway, you no longer have a problem. For the benefit of others, I will answer as if it is still December 2015 and your visa has not yet expired.
If you have missed the chance to renew your visa, and you cannot renew it by briefly leaving the country (which in this case of course you couldn't), then it is generally optimal to overstay and to ask for assistance from the immigration authority. This is especially true with your extenuating circumstance of 9th month of pregnancy -- it is medically risky to travel by air transport.
I overstayed a visa once and didn't notice until I was out of my host country on a business trip -- and what happened to me is that I became homeless until my employer procured a new work permit for me. Trust me, that sucked. If I had simply stayed put, there would have been multiple options open to be to reapply from within the host country.
Disclaimer: Except for sharing my personal experience, I am not qualified to provide immigration advice. I am also not qualified to provide medical advice.