Always getting called in on my days off

I swear I can never catch a break I’m almost 18 weeks pregnant with a 11 month old and I was working full time now I’m working part time so I could get more rest and spend more time with my daughter. But even on my days off I’m always getting called in because someone else calls in and I always go in and it’s so aggravating!! So this time I didn’t even bother to answer my phone because it’s the day I have off but I know when I go back to work I’ll probably here about it. Do I have to go in on my day off because I just didn’t even answer my phone!?

Update: Second day off and they tried calling me in again.