Working momma

I have a question for all you working momma's. How many of you pregnant women out there are having a high risk pregnancy and have let your job know about it and the risk that are involved with over doing it. The reason I am asking is because I've been having a really tough pregnancy. I'm 20 weeks pregnant, I have a heart condition, and have always been anemic due to a blood disorder. Yesterday I go in to work and tell my boss I'm not feeling good if today I could just take it easy but still do my job. She had the nerve to tell me even though I've had doctors notes stating that I'm a high risk that I'm using my pregnancy as an excuse to not work. I'm not nor was I ever the person to ask for help or ask to be treated differently. I feel like this is a slap in the face to me and she doesn't care how much work or stress I have to put up with as long as the work gets done. I work in the health field in a nursing home and it's becoming increasingly harder for me to work but I manage everyday to do my job to the best of my ability and never complain. About it. I am being written up and talked to for the past two days because I dont feel good. I've been nauseous and throwing up since week 4 I've been cramping everyday since I became pregnant but always showed up to work sick or not. I want to know in ur ladies opinions am I wrong for thinking that this is just wrong? What would you guys do if you were in my situation?