Family Opinions

I have four children from a previous marriage and had my tubes tied. I had them untied after being remarried and am pregnant with baby # five for me (# one for hubby). I got my tubes tied after being pressured by family because I had some financial struggles in the past and my mom was very big on career and being an accomplished woman (wanting me to be the same). I am currently a stay at home mom and money is tight but my husband really wanted to be a father (I want to be a mom again, I love children). Having one income has been a complaint of my mother's and I'm so afraid to tell her that I'm pregnant again. I'm afraid she will disown me. I'm 31 years old and should be able to be happy about my pregnancy but can't enjoy it entirely because of this. My mother lives out of state and won't see me for a while after the holidays. It's very early in my pregnancy. Does anyone have any suggestions about how to tell her? Is anyone else going thru something like this?