I had to tell my boss right away because I had already had 2 miscarriages before this pregnancy so I was high risk and I was deathly sick the first trimester I lost about thirteen pounds and I had to miss a lot of work because I pretty much lived in the hospital my first trimester I ended up losing that job due to missing so many days they replaced me not sure if it was legal or not because I had doctors excuses from where I had been admitted into the hospital and the second time my boss actually drove me to the hospital cuz I was at work and started throwing up blood but I'm in my third trimester now and I tell you what its rough I might not be sick throwing up all the time but I have a bunch of new symptoms! The second trimester was by far the easiest but so far nothing has been easy about making another person its hard work!!! Good luck to you hope you get to feeling better
In my Case (having 3 unexplained miscarriages) i have told my boss from day one and the doctor put me on sick leave until I finished my first trimester then she wrote me a light duty report. I am not stressing myself out at work and work on for 5 hours instead of 8 hours a day. It's worth it.