What Is Causing My Chronic Vaginal Discharge?

Hi i am almost 22 and i have 2 children 5 and 2 year olds, ive had virginal discharge for the last 7/8 years but since the birth of my last child ive had discharge constantly not at certian times of the month all day everyday, and its either a cloudy white or a clear stringy mucus it worries me because its a constant thing i am sexually active and been with my partner and only my partner now for 3 years, and ive never had a smear test. what could it be? is it anything to worry about?