Okay, I am going to share a horror story that I will ONLY share with you good people. I've been using the cups for probably over a year with relative success. I use a large yukki on my heavy days and a moon cup for my lighter days, my period is an annoying 7 days. (some minor spotting on the last days). I thought the benefit of the cups is I can leave them in even when I'm super light or before my period to prepare. I've had minor bladder irritation UNTIL NOW. Last night I took a shower and cleaned out my cup, not much was in it but I thought "whats one more day"? Put it back in. Went to bed... woke up in the middle of the night drenched in urine :O Went to go to the bathroom only to find a tiny bit of urine trickling out and a burning sensation but an urge to urinate. I took the blasted cup out. I couldn't sleep for the next two hours because the urge to urinate was so bad. Had to go to work where I have very limited breaks so had to work through wanting to pee all day. In the afternoon thankfully my bladder started feeling better but still irritated. I've never had such a bad UTI before, and haven't.. umm wet the bed since I was a kid. I'm now a bit gun shy of this cup and I am sort of afraid to go to sleep.