does anyone else not feel like a part of there in laws family?

Does anyone else not feel like a part of there in laws? Or your husbands fsmily? I just don't feel like I belong. She goes and buys her sons stuff like for example a cute pair of slippers or tshirts or whatever yet when it comes to me fiancé doesn't see why I would be upset. She comes home today with a Star Wars tshirt and then a Disney shirt for when we go to Disney and I feel left out. Or sometimes they will go to dinner when finance is out of town they will go before I even get home. They say I'm there daughter but I don't feel like it. I have a kid on the way and just feel like well
Both (baby)feel like outcasts. I just don't know what to do. Or sometimes I will tell him stuff and he tells his mom. Or I will ask him why he told her when it has nothing to do with her.