Sonogram is wrong

Jordyn • Birth mother (7 years). 4 year old and expecting in July.
We had a sonogram at 18 weeks. I didn't watch because I wanted to find out at the gender reveal party with all my friends and family.
The lady doing the sonogram said it was a girl. 
Everyone intuitive in my life thought boy. 
I have had 3 signs the sonogram is wrong. A psychic told me she felt boy,  2 woman asked what I was having and said looked like like a boy... Then the name for a boy (which is very unusual) was on display at the library. I feel like the universe is trying to tell me something. 3rd pregnancy and this baby is really strong and has been moving my bump for weeks. 
What is your experience. How often are sonograms wrong. I know more often with a female to male.