I had spotting on the 19th day of menstrual cycle then had bleeding a few mins on10th day of my next cycle. i am not on any contraceptive.what's wrong?

What were you doing : around the time you experienced bleeding? First, did you have intercourse or any other situation like a pap in a temporal relationship to the spotting? Have you had a recent pelvic exam? Are you certain you are not pregnant? Any other symptoms? All these things and more are probably best written down and discussed with GYN. Especially if you have any pelvic pain or other symptoms. Best wishes!

Irregular bleeding: Irregular periods are one of the most common problems obgyns treat. If this is one time problem it usually resolves on its own. If this is a recurring problem you should be evaluated. Infections, polyps, fibroids and hormonal changes can cause spotting. If there is a concern for pregnancy then do a home pregnancy test . There are many options available to help regulate the menstrual cycle.