I’m so sorry to hear you’ve gone through this.
As a priority you need to get yourself somewhere safe - and get yourself checked out at hospital.
I know it’s extremely hard when it’s the man you’ve loved all these years and were building a life with but you also need to ring the police (999 if you can’t get to a safe place or 101 if you are safe) - and do that now whilst the incident is fresh in your mind.
Being shouted at is never a reason to assault someone in the way that he has (the only real defence for assaulting someone shouting at you is if it’s pre-emptive in self-defence - eg person is so much in your face you fear you will be assaulted and push them back or they’re raising fists showing an intention to hit you so you hit them first).
Kicking your pregnant wife in the stomach from how you describe it is just inexcusable.
He may not like being shouted at, he may be stressed, he may have other things on his mind, he could be struggling with something - but none of those are an excuse to be violent towards your pregnant wife!
As you say you don’t want to ever be near him again, contacting the police and accepting support from their support agencies can also help with advice in terms of orders forbidding him from coming near you - or having contact with you (usually there’d be an exception via solicitor or similar, when child care is involved people sometimes have a nominated third party or app for child care arrangements etc) - there’s one that you can get through family court called a non molestation order, family court can also help with an occupation order (it grants occupancy / instructs a part to leave the family home - usually for a limited period of time) and police can also help with applying for restraining orders and domestic abuse protection orders (not sure if they’re are still being piloted or across all forces yet).
In the very immediate term though, make sure you are ok physically (hospital) and mentally (speak to friends/family you can trust)
xxx