hi around day 21 of your cycle day 1 being the first day of your period it takes sperm around 3 days to get to your egg i think your find that your egg is futile for a couple of days so if you have sex on day 18 or 19 they should meet up but the odd women it seems can get pregnant form anytime of the month. don't ask how it just has to be excepted. hope this helps. good luck
when is a woman most fertil and likely to get pregnant