My boyfriend's mom suddenly doesn't like me?

My boyfriend and I have been together nearly three years. His mom and I have always had a great relationship, and has been encouraging us to get married all the time. We used to talk on the phone/FB quite frequently (about every other day), but recently, she has been acting like our conversations are a burden. Normally when someone brings up my future with my boyfriend she gets excited, but she kind of shrugged it off the other day. Nothing has changed in my relationship with my boyfriend, and I do not remember saying or doing anything that might upset her. Is this normal? I'm very hurt and frustrated. She is notorious for disliking girlfriends, and I am the only one she's ever liked.
Updates
+1 y
The biggest stab was that my parents invited his parents to come stay with them for Christmas. We've visited them many times over the years, but they have never been here. Were both in college now and can't afford to travel. She turned my mom down because she "doesn't want to be in cold weather "... Which I feel is a terrible excuse.
Updates
+1 y
My boyfriend just told me that she asked him to move us both closer to them a while back, and he told them that we were very happy building a home and a life where we were. Maybe that upset he
My boyfriend's mom suddenly doesn't like me?
Post Opinion