Did anyone do yoga during the first trimester? Did you attend regular or prenatal yoga? If you attended regular, did you tell the teacher you were pregnant or just refrain from doing certain poses?

I'm 6 weeks and was planning on going to yoga tonight for the first time since I found out I was pregnant. Everything I've read said it is safe in the first trimester if the teacher knows so that you can refrain from certain poses. Now I'm worrying that maybe I shouldn't go. I don't really want to tell the teacher and I really don't want anyone to overhear that I'm pregnant. Obviously I feel like I need to tell the teacher if I go because I don't want to do any poses that would hurt the baby. I'm not ready to go to prenatal yoga because we have only told immediate family and I wouldn't want to bump into anyone I knew. Advice or suggestions?