For those who didn’t find out baby’s gender, did your doctor know even though you didn’t??? Please read rest of the post cause I have a second question!

I’m in my last trimester and after my 20 week ultrasound my dr asked if we found out, after we told her no, I asked if they have to tell the dr’s even if the patience decide to wait to find out baby’s gender and she said she didn’t know if we didn’t tell her! However I had a follow up ultrasound to look at baby’s spine , and found out baby’s a bit small... so when she called me this morning she kept saying “she.... her...” when talking about the baby and the results.... do you think my DR knows the gender and slipped up or that the DR just didn’t wanna refer to baby as “it, they” so she just said the first gender that came to mind??