This may turn out long, SORRY!

So last weekend, my mother and I got into a huge fight. One that we haven't had in a very long time. The argument started out over a bottle of water and escalated from there. she got pissed because someone took her last water and doesn't like the waters I bought ( I currently live with her and my 18 year old sister due to unsafe conditions at my previous apartment ) and when I explained to her it was not me she accused me of lying and it went down hill from there. I'm going to be 29 next week and currently 31 weeks pregnant with my first child so I'm a ball of hormones and can get short tempered fast, however the fact that I'm still treated like a child to this day, and get scolded over something so pointless really has it's limits. When I tried to explain how ridiculous this was especially because I buy stuff for the house all the time and no one has a problem with eating or drinking up what I buy, ( which I never had an issue with )she started screaming at me to basically shut up and in turn I screamed back because I was furious at that point... Now like I said it started out because of water and then somehow escalated to other issues and to be honest I can't remember half of what was said but she told me to get out of her house and that I would be the cause of a miscarriage because of my behavior , and at some point my sister decided for whatever reason to gang up on me and throw in some hurtful things as well . ( She was never part of the conversation at first) And while I know now it was not right to say , I told them that if they both want to treat me this way then maybe I shouldn't have them be around my baby, and that if a miscarriage happened it would be because of the stress they are putting me through. Neither one of them have spoken to me since then and it's been really getting to me because I should have my family during this time in my life..it's always been just the 3 of us . I do have a fiance and he is the father of my baby but when it comes to blood it's always just been us. Living in the same household has made it worse, and at this point I'm not sure what to do. I tried speaking to my sister today for the first time and she basically said everything was my fault and slammed the door in my face, and proceeded to call my mother. I considered apologizing for what I said but im not sure if that's the right path to take or to continue living with this torture until I can find a place..