Hi, I had my period last month on Jan 26 2010 I had sex before this period (unprotected) after my period was done a week later I was very sick for 3 days throwing up almost every hour the first night. I was on birth controll but een off of it for a month but periods have always been on time 28 days it is now 6 days late my breast feel tender and get a little cramps for a second every now and then but nothing major. What can be the cause of this? Am i pregnant?