I have a very light period. When I use my large LC, it only fills to the top of the bumps at the base after twelve hours. When I use it for discharge, it fills to the bottom bumps. My small Lunette fills to the top of the rings on the base with just discharge. It's not everyday. Some days I have almost nothing at all in the cup. My heavy discharge days are about twenty days of the month. I won't wear a pantyliner. Why get a reusable cup for the four days on on my period if I'm going to throw away forty pantyliners that month? And since I refuse to wear a pantyliner (why? because I wear tight pants everyday and only own thong undies. and yes, I have a whole case of thong pantyliners I will never wear again because they wadded up in my butt crack) so I sometimes actually get a wet spot on my jeans before I used a cup. And with the tight jeans and short shirt, you can imagine once I felt wet down there I would have to feel and go check the mirror constantly for fear it would look like I peed myself a little.
So, yes, I wear a cup all day, all night, everyday. I rinse it out before bed, and I wash it every morning. I have been doing this for several months now, and have yet to experience any negatives. In fact, I noticed my undies smell like moist fabric softener, not coochie. I am quite happy with my decision, and wish not to have it questioned. It didn't even have to do with my actual posted question. So I apologize to those who had nicely answered her question for her. You had some really proper answers, and I thank you who defended me.