Since we are under STAY HOME orders, will big jump in births in nine months be a consequence ?

Being that it's almost been a month, I'd say there'll be a big jump in births about eight months from now.  What else there'll be a a big jump in is divorces.  This isn't some blackout of a day or two, which have been known to cause mini-baby booms nine months later, this has been protracted, very protracted, and we've just found out we're in for more than a month more of it.  People are getting on each other's last nerves.  Couples are finding they don't have anything in common anymore and are stuck at home with a veritable stranger that they've lost interest in even trying to get to know.  So look for that baby boom to be accompanied by a divorce boom.

Yes. Like big blizzards where everyone has to stay home.

Not really. Birth control still exists.

We can probably expect to see a dip in birth rates after coronavirus is over, with birth rates only beginning to normalize 10 to 11 months after

Yes, just yes...