Hi,
Am wondering how soon after fertilisation of an egg can a doctor detect a preganancy when doing a test? A few hours days, weeks? Please help

With a pregnancy test (urine or blood) it may be as soon as 7-10 days, but often it will take a bit longer. This is why they suggest waiting until you actually miss a period. With a pelvic exam they can often determine changes to the uterus and cervix after several weeks.