Hiding pregnancy

Hiding your pregnancy physically early on is a breeze because obvisuly I'm way too early for a bump, but hiding my reactions to the dizziness and nausea and hot flashes. I'm worried it will give it away. Normally people around me pay attention so if I'm sick they'll ask what's wrong and if I have no excuse for illness, they'll assume pregnancy and I don't want to lie to them so how am I supposed to hide the fact that I'm avoiding being around my husbands dad and grandma because I dont want around second hand smoke? His grandma has a way of knowing things before you tell her and my mom is the same way and I don't want to lie. I don't want to announce that I'm pregnant until my first ultrasound and until I consult my ob tomorrow (hopefully if things go as planned) and I don't want to be forced to tell someone because they know I don't lie and won't lie and because they won't stop mentioning it until I tell them 🙄 the thought of coming out and announcing just to get someone off my back makes me dread any pregnancy announcement I would have 😪