What Are The Chances Of Pregnancy Having Intercourse Through Withdrawal Method?

hello doctor i had intercourse after a long gap of about 2 years.it was during 17 th day of menstruation.My husband tried by letting the penis out of the vagina by not letting the sperm inside,just by pulling out the penis before the coming of sperm. This was done after 3rd time.first we used condoms for first two times.we really enjoyed that intercourse which was involved with activities to enhance our deep love too.The problem is that usually my periods will come 1 week before the specific time.but this time it has not come yet though the date is 16 that is tomorrow.is there any chance of becoming pregnant?we don't want it now.is ther any way using pills for abortion if it happens and can we do it without medical consultation.kindly give the apt suggestion