When did you tell boss about pregnancy?

I am only 7 weeks pregnant but I’ve been starting to really struggle with symptoms, specifically the nausea and morning sickness. I am having to take more breaks and run to the bathroom to throw up. I had to call off one day and have asked to wfh a few times. I’m worried cause my boss seemed a little annoyed when I asked last time if I could do wfh. Is it too early to disclose? I’m nervous since I haven’t even had my ultrasound yet (just have had a few blood tests) but I don’t want her to think I’m slacking.