I had a period on the 13 of this month and it last for two days and now it's back on.. what's going on.

Need pregnancy test: I would make sure you are not pregnant first and foremost. Stress has been known to cause a second period for women, but so can your thyroid, i would have that checked again. You may have fibroids which can cause intermittent bleeding as well. I would see your md for an exam and blood work.

Unclear: There are many causes for such an occurrence. You should make an appointment for evaluation with your family practice or gynecology physician.