The chance of being pregnant is very low for three reasons:pregnancy
you took the pill before 12 hours(this pill protect around 72 hour after unprotected intercourse
the ovulation is more rare in this ageLevonelle
is very effective and is not recommended for repeated use,as it is possible that it can disrupt your menstrual cycle.
This pill might make your next period earlier or later than expected by a few days,but if the next periods are more than 7 days late after taking this pill ,you should consult your doctor for a pregnancy test.
do not protect from STD
Finally you should consult with your dr for advice about regular methods of contraception.