Not sure about how long you should leave it after having a baby before you have a smear test but just wanted to let you know having a smear test does not hurt, it can be somewhat uncomfortable for about 3 seconds when they do the scraping of your cervix. In the past (pre-pregnancy) i went regularly for them, every 6 months, as i had abnormal cells which they needed to keep an eye on. So for the sake of 3 seconds uncomfort its worth going.