My midwife told me i am having a girl how did she know from my scan?

Absent 'pointer': The ultrasound did not 'point out' a penis making the fetus female.

Saw girl parts: Not seeing a penis does not necessarily mean that you're having a girl. It can mean that the examiner did not get a proper look at the private parts area. My rule was not to say anything about the sex of a fetus unless we could clearly see either the penis and scrotum with testicles or the labial lips. That way we were never wrong! good luck.