Nobody wants to claim my baby

Every since my husband and I separated two months ago, him or his family wants to claim my baby or show any type of happiness for our expected baby. I am currently almost 4 months and during the first month of my pregnancy, my husbands family and my husband was happy. His mom even wanted us to take announcement pictures so that all of his family and my family would know of our pregnancy. But after my husband decided he didn't want to be a family anymore and left me his family has turned thier back on me as well and even deleted our announcement pictures from thier Facebook pages and I am so hurt. I don't know if they are taking up for him and want nothing to do with me just like my husband or if they just don't want to be involved in our pregnancy but prior to our separation they loved me and bragged about how happy they were for me to be married into their family. Since our separation, I've been informed that my husband has been seeing someone else and his family is fully aware of it. When I reached out to some of his family and mom about the girl, they all lied and said they didn't know anything about her and that we needed to work out our own problems but I have proof through messages that they were aware of her and even congratulated my husband on how beautiful she was. Not only am I hurt , but confused as well. I want my baby to feel loved but now that everybody is acting funny...I don't even want them to have nothing to do with the baby when it is born. I feel as if they can't claim it now, then don't claim the baby once it's here. Or have anything to say about how I'm keeping my child away from them, or my husband when they've all done me wrong or lied to me etc.... any advice on this situation??