My Mother will not come to my wedding.

My fiancé and I are getting married next month on October 29'Th. We're having a very small, intimate wedding with immediate family and close friends. The planning process hasn't been the easiest..as my Mom refuses to attend if my step mom is there. They have been divorced for 7 years now and I don't have much of a relationship with my Father's new wife or step sister. Mainly because they don't put forth the effort to get to know me. That doesn't mean I dislike them and I would be happy if they came to our wedding. My Mom refuses to go if they are there, we got into another fight which is something that happens often with her. She refuses to go to my wedding anyway, laughs about it and tells me my brother doesn't like my fiancé. This is the same woman who has invalidated me my entire life, could never live up to her expectations. In July I had a chemical pregnancy and it was a very hard time. Her form of support was telling me "I should of waited to take a pregnancy test". Which made me feel incredibly stupid. Also refused to go wedding dress shopping or help plan anything. She will not attend and makes me feel like everything is my fault. When she's mad at me she will also use the silent treatment to punish me, as if I'm a child again. It truly makes me sad that she's emotionally unavailable & unable to be a mom.