I’ve been spotting for three days but I just finished ovulation a few days ago and my period isn’t due for another 10 days. Why?

Spotting . 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 & 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. Schedule a visit.
Likely no big deal. If this is a recurring problem you should be evaluated.
Agree with Dr. L. Menstrual irregularities are not uncommon and anovulatory cycle is a common cause. If you miss more than two periods it would be time to see your doctor. If you do not wish to be pregnant, use contraception all the time. You may consider implanted contraceptive or an IUD.
Consult this site.
http://www.nichd.nih.gov/health/topics/menstruation/conditioninfo/Pages/causes.aspx
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