AND...if your period was less than 7 days then your chances are even slimmer of actually being pregnant...
Three days after your period ends? Depends on how long your period lasts...If you have a 7 day period and you have a question about it happening on cycle day 10 then it is somewhat likely but not super likely...cd10 would be a little early considering that most (not all) women ovulate around cd14-16 depending on their luteal phase...Sperm only realistically live 2 days although some literature says 3-5 the average sperm usuallly only lives 2 days (check out Fertility Friend's website I just read a literature review about this) SO on cd10 you most likely hadn't ovulated yet so there was no egg in waiting, and if you had the sperm deposited on the 10th perchance they'd live till the 12thcycle day and then die before you even dropped your egg...My opinion is that you are probably not pregnant BUT there is always a possibility...Good luck!