Confused and worried!!!

[tinytummy]

Though I am not taking any BC pills, I took one morning after emergency pill after having an unprotected sex with DH. I found out later, it was most fertile period of my cycle. Plus I am on few multivitamins supplements (B vitamins and Vitamin D for some other conditions) which I know can make my body most fertile and easy to conceive. Now, I am worried, I have 28 days cycle and I am 4 days late. No sign of either AF or pregnancy yet. Could I be pregnant without any symptoms? I was not having any symptoms in my 1st pregnancy as well except fatigue. Can morning after emergency pill can delay or extend your cycle? Any experience?