Ok so I have a lily size a which I have used for one cycle and I'm happy with it after trimming the stem right down (it fits nicely now and is still easy to reach). However I wore it to the gym and it was coming down because of muscle use and probably length, so I'm thinking of getting a second, slightly shorter, stiffer cup for exercise and for lower cervix days when it's a tiny bit too long to be comfortable. Any recommendations based on the lily? I was thinking of a large Classic meluna but I'm not sure if it will be too wide or too short. I've looked at all the size charts but I'm just overwhelmed by the choices.