My mom

So I'm currently pregnant with my third child and have two small kids. I've been living on my own since 18 yrs old I'm now 25 and still with my husband . My mom and 27yr old brother live in a two bedroom. My mom doesn't know I'm pregnant and I honestly feel like I can't talk to her she judges everything and then talks shit with my brother about me to other people .I love my mom and everything but I feel like if I tell her it will all be negative . Yes eventually she will find out but until then I dont want to say anything to her !!! My brother and her always have some comment to say towards me not that we have a bad relationship, just disagrees with me a lot !!! What should I do?