Usually my period comes around the same time each month, which is around the 8th. The last two months it has come a week earlier. This month it didn't come the week early. It's the 8th now and it hasn't come. Should I worry? Or could stress be affecting me?

Stress can definitely make you late. But if you think you might be pregnant it's best to take a test to find out for sure. And if the test is negative and your period still never comes you might want to call your dr

A lot of things can affect your cycle such as stress, moving to a new location, changes in diet or exercise, etc.

I agree with justcurious55 to take a hpt.

I would hold off on the HPT for at least 4 - 5 more days. At this point, it may be nothing and your period could come in no time.

Its not uncommon to have irregular periods ~ sometimes you'll start early or late for no real reason.
If it would make you feel better though, take the HPT. :)