MIL from hell

I just need some advice..I live with my fiance and his mother at the moment. It's all good, except when it comes to her. I'm 37 weeks pregnant, and she has absolutely no respect for me, for no reason at all. Last night, my dog was really sick and had an accident on the floor. She came in our room and told me "the dog shit, this ends tonight" and went off ranting on how I need to get rid of the dog because I'm pregnant and needed a little help bending all the way down to pick the poop up off the floor. Then, this morning she came in me and my fiancee's room, and told us that it looks like a "junk yard", that we need to get rid of our couch because her youngest son wants it in his home, and move all the babys stuff out of the way today, and if we dont, she will come in and throw it all away. (Mind you, our room is not a mess at all, it has some baby stuff lined against the wall waiting for him to arrive.) I just dont know how much more I can take. Its like this every day. What should I do?