I've been using a Diva Cup for six to eight months now (I can't remember the exact month I got it anymore) and by the spring of this year I thought I'd had all of the problems worked out. I am now to the point where I can insert it without any problems, pop it open, make sure it's seated properly around my cervix (O), spin it to make sure it's sealed and wipe the residual slobber (when there is any - there often isn't) from around the outside of it.
However, the last two months my body/Diva Cup has been playing a new game that's not in the least amusing and this morning resulted in me scrubbing menstrual blood out of my mother-in-law's baby blue bathroom mat. (This is why I also hate bathroom mats - I just have tile when it's up to me.) It seems that, on my heaviest day (and only on my heaviest day, no other time during my cycle) my Diva Cup will leak when I go from a reclining position to a seated/standing position. This means first thing in the morning when I wake up (hence the disaster this morning - the floodgates opened this morning during my morning bathroom routine, and NONE of it made it into the cup - a whole night's worth of bleeding made it on to the floor) and any time during the day when I might be reclining - on the sofa to watch tv, to read a book, etc.
Any other position is fine. Just a few minutes ago I had a leak from reclining. Between this morning's disaster and the current one, I had gone on a twenty-minute brisk walk with my mother-in-law and dog, had worked on the computer (seated), had been up and down from my chair several times, no problems, no leaks, no discomfort. Leaned back to read a book for about ten or fifteen minutes, got up to answer the doorbell, and on my way back to my room - bam. Leaking. I felt it immediately, so thankfully there was only a small spot in my underwear, but it annoyed the CRAP out of me. When I took my cup out to check it, it was half-full, which meant it had worked all morning UNTIL that point.
I've looked through the leaking tags, and I know some others here have posted similar problems with leaking when they first get up or when they're reclining, but I haven't seen any posts with a definite solution to it. :/ I looked at the size charts in case it may be a problem of stiffness/size, and the Diva Cup is one of the big(ger) cups out there. Am I just going to have to try to never recline on that one day of the week, and/or buy cloth pads for the overnight hours? I'm no stranger to the "mad dash to the bathroom" first thing in the morning, as my period used to START then, and I could sometimes make it to the bathroom before I stained my underwear. However, I'm going back to college for my Master's degree this fall and will be living in the dorms again - which makes the "mad dash" nigh impossible, because even if I were to make it down the hall, there's no guarantee that any toilet or shower stalls will be available. :/