Given the data you provided, you might be experiencing ovulatory (mid-cycle) bleeding. Mid-cycle bleeding occurs at the same time as the ovulation. The reason for this bleeding is the change in hormone levels that occurs during the ovulation. Sometimes the change can be so big that light bleeding might occur. This condition is not considered serious. You might want to visit your gynecologist if the bleeding lasts for several days or grows heavier or repeats the next cycle. This bleeding will not affect the start date and duration of your next period or the blood quantity lost during the period.