Are you sure you are not just having another period? Sometimes they can occur close together, particularly if one is under stress (stress can trigger periods.)
Is the bleeding heavy? Is it regular or just spotting? And did your period actually end a week and a half ago, completely, and then out of nowhere you began to bleed again, or have you been bleeding continuously?
If it concerns you, I would see your gynecologist. My mom had an ongoing issue with bleeding that lasted like a year and a half, and her one gynecologist kept telling her she was fine, but never physically examined her.
She tired of this and found another doctor, who physically examined her and found out she had a pollup (sp?) Once he removed it, her bleeding stopped.
Long story short, make sure it is not just a period going slightly too long, and see your GYN if you feel unsure!