My fiance, his crack head mom and the Valentines day drama. Was I wrong? *UPDATE*

Okay so here's some background first. I am engaged and 10 weeks pregnant with me and my finances 1st together. I have 2 children from a previous marriage and he doesn't have any. My fiance family is so disfunctional and ghetto! His mom smokes crack and drinks on top of being bi-polar. One of his sisters sells drugs 3 of his brothers are in jail doing more the 2 years. They are just all over the place. My fiance is a real nice guy and not like them but as soon as I got to know what they were all about I distanced myself and my kids from them. I don't go to their holidays or parties we do our separate thing with our own familes. So we moved in together 2 years ago. Are apartment was not ready until the 15th of the month we were in and we had to leave our other apartment by the 1st so for 2 weeks we were going to stay with his mom. Please keep in mind at this time I didn't know much about his families ghettoness and craziness. So me and my 2 kids (9&3) stayed with his mom with him for what was supposed to be 2 weeks. Well I quickly began to see what was going on. His mother was insane with bipolar plus drugs and alcohol. His sisters having drugs on them it was just too much. I had 3 days before are apartment was ready so I stayed away all day and only came to sleep. Well... that night his mother had a drunk and high rage and said my son's crying and whining was "killing her high" and told me and my kids to leave. Mine you it was 1 am and I had to take my kids and my stuff and leave with no where to go as my family lives about a hour and half away. I ended up going to a shelter for 3 nights until my apartment was ready. I moved in myself at first because I was so upset that he didn't leave with us and that his mom did that to me and my kids. His exscuse was it is her house and what could he do. Anyways we worked thru it and he moved in with us 6 months later but I have still always held so much anger towards his mother for what was done. What me and my kids went thru.... flash forward to present day. So again me and his family don't talk much. They aren't my class of people and I just feel like being arround them endangers my kids. His family feels I think I am better then them and try to keep him away from them so they don't like me much either. I let him go with them whenever he wants it's just of course I want better for him and always try to let him see that being a round them alot isn't good for him. For the record even though his mother has tried to "apologize" and talk to me I don't talk to her at all. She still smokes crack and drinks, doesn't work just collects off the state and I also can't get past what she did to me and the kids. So today.... Valentine's day. She calls him and says her life is in danger. When he calls her he finds out that his mother's on again off again boyfriend (who also uses drugs and drinks and doesn't work) has robbed her daughter (who sells drugs) and her boyfriend. He stole a gun, 1000$ and some drugs from them. But again this is not the first time he does this shit and she always takes him back. Apparently she told her daughter it was him and he tried to kill her. She called the police and he left so they didn't arrest him yet because they haven't found him. So my fiance comes running to me and says can we go get my mom? ...and explains what happened. I said no. First of all I feel this is her problem. She continues to let him back in her life time after time when he does these kind of things. But also his step dad knows where we live and am pregnant and have 2 children here. If she is so much endanger that she needs to leave her home then why would it be ok to bring her here and endanger me and my kids as well as we live 5 minutes aways from her. On top of that I am still extremely mad she thru me and my kids out at 1 am because she wanted to get high and drunk 2 years ago. I told him absolutely not. And if he was that concerned he can go there or go get her and go to one of his many sisters/brothers houses but not here because the kids and I are here. He got so mad at me and left furious. He then sent me a text estate stating that now he sees how he can't depend on me for anything and he loves me and if something happens to him I should know it was my fault for being so "stubborn". I am in tears. I can't believe he would act like this with me. I don't feel I was at fault or wrong for saying no she couldn't come here. I also now am home alone pregnant with 2 children here and a crazy man with a gun running arround town hoping he doesn't show up here. I feel like he abandoned me and my kids safety and left us for dead to go rescue his crack head mother. I know it's immature of me to say that but that's truly how I feel. I am taking my kids and leaving to my parents even though it's a hour and a half away I just don't feel safe here. I also want to add we have plans for the whole rest of the day for valentine's day for me him and the kids that he just blew off for this. I am just a mess right now and I really need to ask if I am over reacting or if I made the right choices. Even if this costs me my relationship my children's safety and my own are so much more important. Thanks for listening.

*UPDATE*

Thank you everyone for your reassuring words and support. I made it with the kids to my parents and we are safe. I think right now it's best I stay away for a little while and just figure somethings out. I have so much going on in my head now. Even though he does completely understand how wrong he was and has done nothing but apologize I do still feel so hurt and also am now questioning so many things I never did before. With that said I just need some time and space to figure things out and do what's best for me and my children. Best wishes to you all.