Is it possible that a person that once tried to scare you by hitting or almost choking you is never changing?

I met this person on my space nov, 2009 i was married then, and well we went out a week later had intercourse we both fell in love, he was so romantic he was different to all men i"ve met, i went to live with him on feb 2009 but got problems amd went back home with my husband, then i stopped talking to him but a week later he started sending messages again on my space, i dont know but the minute i realize we were bavk together, thid happen all year, but on oct. Nov, december of last year i went to live with him those 3 times and went bsck home. On those 3 times he kick me pulled my hair with baby in my arms, he tried to choke me. And told, me that hell kill meand throw me in a black bag. So no body could find me. I left went back to him 2 more times he insult me hes jealous, he tells me things he did with previous girlfriends, he told me i was crasy stupid he never gave me my car keys do i couldnot go anywhere, i was really scared, and this last time my husband let me in back home i assume hes worth netter than this other guy. But now hetells me he have chamged and he"lll never hurt me again to go back with him go luve together, im even pregnanr by him we had sex in 24 25 26 of dece,ber and never saw him again but my husbamd dint know is his baby...do u think this guy really has changed i gave him a lot of opportunities, will, this be the true one? What do u think peiple out there? I love this guy and now i should"nt..