I Am 22, I Have 28 Days Menstrual Cycle I

I am 22, I have 28 days menstrual cycle I had unprotected sex on my 3rd day of menstruation, were my blood flow was average. I took the measures to not to get pregnant that is I had contraceptive pill on 3rd day after intercourse. And I again started to bleed after a week having that pill. And now I am 3 days late considering my monthly date. Does this mean that I am pregnant already?