Is there a chance I am pregnant?

Patient: I had a very weird period this month. It came two days early and came off and on through out the 5 days I had it. I usually have it solid all the way through. 7 days min. that I have it. I have sex with my boyfriend on the 3. Got what I thought was my period on the 8. Is there the chance I am pregnant. I didnt use Proctection. I am worried. Can you help?