I had a blood test and found out at 12 weeks

Yes you can! I found out the sex of my son at 14 weeks at a 3D ultrasound ☺️

I've heard mommas on here talk about a harmony test? it's a blood test and the earliest I think I heard get a gender was 12 weeks?

you can with a harmony test

I was told it's possible. but not 100% sure.