it is also common to get extra mucus when you ovulate, and that might be some of what this is, although I agree to get it checked. This mucus would be maybe a little more than a week before your period starts, but it would depend on how long your entire cycle is. This discharge is perfectly normal and its function is to help sperm swim up there and make babies. It would coincide with "mittelschmerz" a german word that means the pain in the middle (of the cycle) that some women feel at ovulation. I often felt like I had appendicitis. You do not switch from left to right ovary month by month, by the way. That might make sense, but it ain't necessarily so. I rarely "shot" from the left, who knows why. Kinda makes you wonder how this works for boys, but maybe that's TMI at this point!