Why is it so hard for my mother to care?

Shelby • •Oilfield Wife💍 •Hulahooper •SAHM •FL🛩OK •Two amazing fur babies •November baby coming soon 👪
When I was 8 weeks my husband and I decided to finally announce to the family that we are having a baby. My mom attended and seemed happy (so, I thought).
I am now 11 weeks and have not received one single phone call or text from my mom asking how I'm doing. 
My Mother-In-Law (who just recently came back into my husband life) will text me every other day or every two days to ask if I'm doing okay, or if there is anything I need.
To add to all this! My birthday just recently passed on the 22nd, and my step dad sent me a happy birthday text. Not even my own mom could call me to wish me a happy birthday. To top it all off! They know I don't work and both had the day off and they didn't even offer to spend any time with me. My MIL took me to lunch.. 
I don't mean to vent, but so far! My mom is the only thing that makes me emotional during this pregnancy, and I don't know what to do :/