Gender

I had my 20 weeks u/s last week. We were so excited to finally know about the gender. But the sonographer was rude, she just had a quick look and didnt show us anything on screen and then she said “i think its a Girl but I am 90% sure, Dont paint the nursery pink and dont go mad on pink clothes” Now i have thoughts that may be she is wrong and may be its a boy instead of girl. What should i do now?? Help please??