Menstrul cups

Anybody else having a hard time using these things?? When I first got mine, my first few months on it were a breeze!! Worked amazingly! No leaks, no havoc, no stress! Now all the sudden I can't seem to keep them from leaking! It's really frustrating, because my job requires I work out and that I'm active, and pads just don't work that great with that environment and tampons are not only terribly riddled with chemicals, but also make my cramps super bad. I thought a cup would be the end to my nightmares!