Scared gender is wrong

So we went for an elective ultrasound at 13 weeks to find out the gender. The tech said she thought a girl, but she was still swollen so wanted me to come back at 14 weeks. So at 14 weeks we went back to a different tech and she said 100% positive a girl. We then went to a dr appointment at 15 weeks and had an ultrasound and the dr said she agreed now doubt a girl. We already have three boys and I'm just sick to my stomach every day that they could be wrong about it being a girl. How many of you had early ultrasounds and could you post pics??? I'll post some of my baby