thanks for query.
first of all in my opinion always use a condom it will not only protect you from pregnancy
but from STD
also,so never do sex with out condom.
there is no safe time to do sex without condom,chances of pregnancy always be there.
because you have sex in period day and not ejaculated inside chances of pregnancy are very less.
wait for next period if it not come go and consult gynae to rule out pregnancy.