What would you do or think?

Brit
Okay my doctor told me at like 15wks I'm having a boy..& at 17wks a 3d ultrasound place tells me I'm having a girl..
What would you do???
In a week I have my anantomy scan which I'll be a full 20wks..I was thinking if I end up with another result..then I would just wait till the baby is born to have a bbyshower..also this has happen to my broNlaw the 3d place told him a girl & he ended up with a boy..