I Had Sex On 7th Day Of My Periods.took Unwanted

I had sex on 7th day of my periods.took unwanted 72 next morning(11 hours after intercause).Had withdrawel bleeding after 7 days and persist 2-3 days.is any chance for pregnancy.i am safe?After 1 week of withdrawel bleeding i have right side back stomach pain in the place of kidney.is it ba of ecptic pregnant or due to kidney stone.on both sides.right side is more pain.