You can do a blood test at 10 weeks I found out at 15-16 weeks with an elective 3D ultrasound. Honestly would recommend getting one the experience is great and the techs were so much more kind than the ones at my doctors. Going again in a few weeks when I turn 30 weeks because it was just that great!
i had my 10w app. today and my ob was "like if the baby un crosses the legs i would tell you what your having" witch my baby didnt 😭 i thought it was kinda wired since its that early but to be safe its better to wait around 15w in some doc. offices or you would have to pay for a private one