Gender results!

I just got my harmony test results it’s a GIRL!! Husband and I were hoping for a boy but we’re still happy regardless the gender. The only thing I’m confused about is that I’m 13 weeks 1 day today and the form says I’m 13 weeks 5 days so I’m super confused bc I don’t know if the baby is measuring bigger than what iam so if anyone knows what it could be I would appreciate it.