First Specialist Appt 12 wks 4 days

I went to my first MFM specialist appt today. I was told because I have a thin uterus I'll most likely go on bedrest around 20 weeks and worst case scenario they will take baby at 32 weeks but most likely will be 34-36. They don't want baby getting bigger and rupturing my uterus.

Also, they tired to tell gender but couldn't. I heard something about nub theory. Is this a good pic?

Heartbeat was 161. My first OB appt was 3 weeks ago and it was 182 then.