What Are The Early Symptoms Of Pregnancy?

I have a pattern of irregular periods. In January I got it for 3-4 days on the 14th and then again for a day on the 1st or 2nd of February. On the 14th of February I was having vaginal sex without real penetration with my guy wearing a condom. He came outside my vagina. However after cuming he did not take off his condom and his penis became flaccid. I was on top of him for a few minutes before I realized that the used condom was in my vagina with his ejaculation in it. I thoroughly washed my area and took an ipill within the first two hours of this episode. On the seventh day after taking the pill I have stomach pain and had bleeding which is very much less than my normal and hasn't lasted. I read about implantation bleeding as a sign of early pregnancy and am a little worried. Please guide.