Does anyone know the laws if you use up sick time

I had bleeding, the flu and stomach bug that hit the first couple of this pregnancy. A co-worker said she heard our boss ask hr if “ he should write me up for this”. You can’t legally write up a pregnant women who was sick and pregnant? I just want to know if I have fmla on my side. I went to doctor each time, so it should be documented. I just feel like he’s playing with Fire.