first trimester scan gender reveal?

Taylor
I have my first trimester scan tomorrow! At my 10 week appointment with my OB GYN she said they might be able to tell me the gender tomorrow?! I'll be 12 weeks 3 days tomorrow. How many people were told the gender of their baby at this scan and how accurate is it?! 
UPDATE: BOY 💙💙💙💙 90% accurate. They'll confirm it in 3 weeks thanks for all your input!