Blood test showing different gender as ultrasound..

selena

So I have recently got the NIPT blood test to tell me the gender of my baby when I was 13 weeks and 3 day.. the test results came back as a BOY and now that I’m 16 weeks 3 days my ultrasound technician is telling that she is almost definite that I’m having a girl I’m so confused at this point and anxious to know the gender..Has this happen to anyone else??