Getting an early period could be down to several things and one of them is that your cycle has changed.
Here are a few questions to ask yourself:
- Has anything different happened?
- Have you been stressed, started a new job etc?
All these things can bring a change to your cycle.
- Is there any possibility you may be pregnant?
I only ask because an early 'period' can actually be an implantation bleed, so if there is a chance that pregnancy is the cause, and it would be a good idea to take a pregnancy test.
If you aren't pregnant and everything feels normal I wouldn't worry about it too much. Wait until next month and see what happens, if things are still worrying you then it might be good to see a doctor just to be sure there is no underlying cause.