job help!!

Bre`ana
I recently was fired from my job of a year before I reached 16 weeks because I was very sick in my first trimester which wasn't convenient to the job. I recently landed a job as a concierge for an apartment building. I'm currently 19 weeks pregnant and haven't told my job for two reasons. One reason is because I was hired through a temp agency and I haven't told the agency. The second is because I didn't want to be over looked because I was pregnant. I'm wondering when would be a good time to tell both parties that I'm pregnant!!!