In a normal 26-31 day cycle, ovulation usually occurs 14 days ahead of the next due date. Alternatively, the period from 8th day to the 21st day is considered fertile and the rest of the days are considered safe to have unprotected intercourse
.Since you had unprotected intercourse during the safe period (presuming you have 28-30 day cycles), your chances of conception are less likely. It may be a delayed period. You can wait for a couple of days before testing for pregnancy
. take care.