Am I wrong here?

Ok so long story short my mother is so overbearing. Sometimes I can’t handle it or don’t have the energy. I am almost 30 weeks pregnant also have a 13 month old at home. Today I just finished my shift of working and I was just exhausted. I’ve worked about 3-4 days straight and my job is CNA work. I get up at 4:30 in the morning to go in to work. Today after work I came home my son is teething and been super fussy so handled him for awhile my bf made me some food! Then I got tired and my bf let me lay down and take a nap while he watched our little. I wake up to constant missed text messages and missed calls from my mother. She wants to come over and do some stuff for the day but I’m exhausted. Mentally and physically. This morning she even texted me while at work blowing up my phone saying I bet you are so tired today. I just don’t know how to respond without being a total bitch at this point or how I should go about the situation. I’m 21 and live with my bf and our child. She still just treats me like a child sometimes. Super annoying. What would you do to handle the situation the best way possible ?