You have to wait until 18 weeks so just over 4 months, anytime before that and the baby's genitalia looks similar. At any point before the 18 weeks the doctor can't tell what gender it is. After the 18 weeks the baby has developed enough that is it safe for the doctor to do an ultra sound and see what gender the baby is. But it is always good to ask how clearly your doctor can tell between the babies genitalia.
How soon
no
He will work out roughly how long ago it happened from the baby's development, then ask you when you had sex around that time.
No the pregnancy test lone will not tell you the sex of the baby.
Have what ? sex? a baby?
No
The baby's genitals aren't developed enough to tell yet.
at 6 weeks you can see the heart (it will be a very tiny circle that is beating) and see a small oval shaped fetus in the uterus. you cannot tell this soon about the sex of the baby or any other features like hands or feet. the sex and baby's features can be determined at about 21 weeks on ultrasound.
5 months.
you should as the vet to find out
Around week 18
5months