When did you tell close family about your BFP?

Samantha
I'm about 3 weeks along and going to be spending 4 days with the in-laws on a mini vacation. My mother in law is a nurse and very perceptive so if I don't say something she might just figure it out especially if I'm not drinking. I am not too worried about it being frowned upon because of the chance of miscarriage, but is 3 weeks just too soon?