pregant

I had my period on 9-17-06 and I had unprotected sex on the 29th and 30th of sept. My breast are very sore and i noticed my nipples are hard and they are so sore. I have had some nausua but i am wondering it has only been a week after i had sex and i feel like this. Maybe i have a touch of the flu bug. Do you think the sign of breast tenderness is anything ? I am tummy sleeper and i have large breasts maybe they are just sore. sometimes i feel as though i could throw up i would feel better. Do you think there is any thing to worry about ? thanks