16 weeks Gender ultrasound 2 soon?!

So tomorrow I'll be going to find out the gender of our 3rd baby (or at least try) I'll be 16 weeks and 2days..With my other two pregnancies I never went his early to find out so I'm kinda nervous they won't be able to tell! And me being a plus size mommy I'm wondering if I should wait a little longer..anyone else had a scan this early and they were able to tell the gender?!?