I'm not suppose to get my period for another week, and I started bleeding this morning. How do I know if I'm pregnant or if it's an early period? My boyfriend and I have been trying for a baby but I don't have any kids yet so I don't really know what to expect. When should I try a hpt?

That depends. Sometimes, at about a week before your period should start. You can get something called implantation bleeding. This happens when the egg plants itself into the uterus when pregnant. It does not look like regular period blood, it's usually pinkish or brownish I hear. It is also very light, so there should not be much blood. Keep in mind that implantation bleeding is not very common.
Then again, maybe you have an irregular cycle and you have just started your period early.
The best thing to do would be to take a pregnancy test a couple days after your period is due. It is useless to make assumptions right now, they could get your hopes up for nothing. A pregnancy test is the only sure way you will know.

That being said, best of luck and take care!

If it is a regular period, it is most likely just a period, many women have them off a week plus or minus all the time. Normally it is missing, a period, not a early one.
If this is extremely light and only lasts a few days, that is different