Bridesmaid Lack of interest..normal?

I am currently struggling with the lack of interest that my bridesmaids are showing in my wedding. I am the last to get married...leaving all my bridesmaids having babies and mortgages now. I have been certain to not talk about my wedding unless it was asked about... which has been once in 6 months between three of them. (Two of the five are my sisters and have been somewhat helpful.)This wouldn’t be such a big deal but I’m a tad heart broken because I was constantly checking in and being with them every grueling step for their big day when I was their bridesmaid. Am I being overly sensitive or is this normal? One of my BM’s who will have to travel to be at my wedding has even stopped responding to texts asking about how her baby/job is! Thinking about giving them an “out” especially since my wedding was just pushed back to 2019. Has anyone experienced this/have an “out” how did it go?