I started my period on Friday 1/29/2010, which was the expected day. My period have been very regular for quite a while.

Hi, Chillintherain,

Welcome to EmpowHER. Your nickname makes me want to get you a sweater!

Thanks for your question. I have a couple questions for you.

First, did anything change this month? Did you start or stop any medications, or increase or decrease an exercise program, or change a diet? Have you been under a different amount of stress recently?

All those things can mess with our hormones and affect our cycle. It's quite possible that one of those things could be the cause.

If you've had that long of a period -- even though it was so light -- then no, you wouldn't be pregnant. What generally happens in some women is implantation bleeding, which tends to be more like spotting, and just for a day or two.

Here's an explanation of this kind of bleeding:

http://www.babycenter.com/404_can-you-be-pregnant-and-still-get-your-period_7102.bc

Are you trying to conceive?
Or are you on birth control pills?
DId you have unprotected sex around the time of ovulation?
Were any other usual symptoms there? Like cramping, bloating, etc. Were they milder than usual also?
Are you underweight?
Have you ever had ovarian cysts?