partner keeps me awake

I can't cope sleeping next to my fiancé. I don't know what causes it but when he is in a deep sleep he jumps. His whole body literally jerks and it drives me crazy. I have tried telling him about it even have video of him doing it but he won't see the doctor about it, he barley even believes me telling him he is doing it. He doesn't wake up, it's me that gets woken and then gets kept awake. Our first baby is due in 7 days and I won't be getting any sleep at all at this rate with being woken by her every couple of hours to feed and him jumping keeping me awake. I know it's not his fault and I feel bad waking him up because he is doing it as he has to do a 10 hour shift at work the next day and im currently on maternity leave so could just rest/sleep during the day. It's just frustrating!!!