Disappointing anatomy scan

Today we had our anatomy scan done on our baby boy. I went in thinking that I was 20 weeks and a day. I was very excited for this appointment. Unfortunately my ultrasound technician was not so pleasant. She was so rude, she was very uninformative and basically just talked to herself a few times. Most of the time we just asked her what she was looking at and she talked to us like we were stupid and should have known. After the first couple of times she just started ignoring us completely! Thank god we had an elective ultrasound at a different facility to find out the sex early because this was a terrible experience. Luckily we have to go back in because she couldn't get a measurement of his head. She took tons of pictures on the machine, and then printed three of her own choice... As we were leaving she said congratulations in a little sarcastic tone... Did anyone else have a similar experience? She said that my doctor would give me results of the ultrasound at the next appointment... I was very disappointed. But I noticed while she was measuring everything the ultrasound machine would say 21w6d and things like that and some of the pictures say like 13 oz but my books and apps all say my baby is around 9-10 oz. Could that mean I'm a little bit farther along or would this affect my due date?