Sounds like a very good thing the relationship was so brief. He sounds like a horrid person!

As far as the dating scans, lots of people have them, but lots of people don't. You need to do what is best for you and your baby because all this stress is no good. I'm really not sure how you should deal with this, but you need to look at what YOU want. If it were me, I would be telling him he can either be involved and be civil, or if the abuse is going to continue, then he won't be involved at all. If the abuse continues and you decide he will not be involved, you may even need to look into changing your number and possibly even speaking to the police about an order to prevent him contacting you.