I've worked in the DV field for many years, and often the abuse escalates during pregnancy. It would probably be easier for you to get out sooner, rather than later, when you are further along. Having police officers next door won't necessarily keep you safe.
I second EG's suggestion that you contact a DV advocacy center for some safety planning. It sounds as if you will have some good resources to support yourself and your children, but you must remain safe in the meantime and get to a safe place as soon as possible.