White discharge can happen for any number of reasons at any given time in a female's body. However if you're having unprotected sex and you've not been checked, you can never rule out an STD. Before you engage in sexual intercourse with someone you should ALWAYS find out their status. People have no reason to ever be honest to you--if they are and say they have herpes or AIDS you likely won't have sex with them.
No, it means either your period is coming if it hasnt already, or that you may possibly have either a uti or a yeast infection. You should go to your doctors and let them know of this white stuff, they will have you pee in a cup. Then examine it, then give you the results. You can even take the test yourself. Take a clear cup and pee as much as you can into it. If there is stuff floating in there, aside from the large droplets of white sticky stuff, then its a yeast infection.... If you have pain along your back ad one of the sides of your body, then its a uti.