Had protected sex on 16th day of my cycle. Cycle lenght is of 26 days from last 4 months. Expected ovulation date is 12th of cycle ( had egg white cervical mucus on 10th & 11th of cycle ), he was wearing a condom and he didn't ejaculated inside, he too checked for any leakage or breakage by filling water and blowing air, no breakage was there. Now my periods are delayed, had a little brownish discharge and spotting, took pregnancy test on 28th, 29th & 30th all were negative. What could be the possible cause of delay. P.S. - from last 4 months my period blood flow decreased instead of 5-6 days my periods started to end in almost 3 days.