it depends on how accurate your monthly menstruation cycle....if you period takes abt 5 days & plus 2 days after period which on the 7th day have sex, & provide semes live for 3 days, it reach the 10th day....theoritically it is save as ur ovulation is on the 14th day...but it also dangerous if you cycle is not accurate, as it may ovul on earlier than 14th, then u may pregnant....
Just wait for your next period, if come or no come, jsut go phamacy get the pregnant test...Dont play guessing....simple as it is...

I doubts is it safe to have intercourse during pregnancy...1st month onwards?Besides, why some woman get diabetes after give birth?Why & how to prevents it?