Fiancé leaving for Christmas...for days!

Girls I’m literally so heartbroken. My fiancé just told me that he’s leaving Friday to go spend the holidays with his child’s mother and her family. In the past and just last month I found messages from her saying “I love you and miss you” and he would say it back. He said he was saying it to his daughter and that it’s not what I think. I broke down in tears while making dinner because he knows I’m uncomfortable with all of that and now I have to deal with him being gone for days. My kids hung up a stocking for him and we were all under the impression that he would be here with us on Christmas. His daughters birthday is supposedly on Christmas so I feel like why does he have to spend all those days in another state with them? He says he HAS to entertain her family as well on Christmas by going over there that day but AGAIN why all the extra days. I asked him flat out are you going to sleep with her, he says no. He says he’s going to be staying in a hotel not at her place but that doesn’t make me feel better at all! I asked him what if she tried to sleep with you? He says “why would she when she has a man?” Like that’s ever stopped anyone from cheating...it sure didn’t stop her from sending “I love you” messages to my fiancé. He doesn’t understand why I’m questioning him and why I’m so hurt by it. He says oh I just want to eat and go to bed. So AGAIN I’m left sitting here in tears by myself. He doesn’t make me feel better about it by saying anything. He just said I don’t know what to tell you. Oh and I’m almost 7 months pregnant with OUR child. I’m so sad ladies😭😭😭😭😭😭😭 what do I do?