It could just be normal discharge - I get quite a lot and you can read my post under women's health, as i'm not sure whether mine is normal or not...
I saw the doctor about my discharge, as I get it every day and it always stains my knickers so I was worried, but the swabs the doctor took came back negative for bacterial or yeast infection so mine must be normal!
I think everyone gets some discharge, especially in the middle of your cycle when you are ovulating and in the week before your period. But it is definitely worth telling your doctor to rule out any infection. You can tell if it is worrying by its colour - normal discharge is white/cream (sorry if that sounds gross!)