Making me feel bad about my pregnancy..

This has been really heavy on my conscious lately... I am a nanny, and the woman who employs me has been super negative about my pregnancy. I told her very early, as I know I’m not going to work anymore after I have my son, and I wanted to give her plenty of time to find another sitter/nanny. She literally sat me down as if I just told her I was dying and continued to tell me how her last sitter reassured her she was on birth control... wtf?

I am under no contract, and work part time, also her children are not babies anymore. They’re all in elementary school now.

Lately I have felt uncomfortable because I am now 21 weeks pregnant and she hasn’t told the children. I am definitely showing, and feel so awkward being at work with my belly. Also, we have a mutual friend who I sit for occasionally who has told me that my employer has said things to her about my pregnancy, like I’m too young and sounds kind of like she feels sorry for me! This pregnancy was 100% wanted... I was not on birth control and we had been trying to get pregnant for a couple years. I am not married, so I know this makes some people judge me a bit, but no one has made me feel this badly.

All of this being said, I obviously just want to quit! I feel so disrespected and hurt... this is such an important time in my life. I feel that by taking this treatment and dealing with the anxiety of working for her, that I’m almost disrespecting my child! He is literally my life now, and to be made to feel silly or stupid for that is just heartbreaking. At the same time I’m dreading the fallout that will surely follow quitting. I know she will keep pressuring me to stay on or downplay what I’m feeling. At this point I feel like by not addressing it, I’m letting her weaken me though! I’m not totally sure what to do... or maybe I am sure what to do but it’s just so hard and awkward to deal with. Help?