Okay, so I'm 27 and have never given birth, and I've been using a Diva size 1 for about seven months now. I always felt somewhat smug that it worked PERFECTLY for me from day one- easy to insert, no leaks. Wee! Well, last month, out of nowhere, it started leaking like crazy. I thought it might have been a fluke, but it's happening this month too. My instincts tell me that maybe I need a size 2 now, but I thought I'd ask you all first. I'm sad that my vagina seems to have grown overnight because the idea of shelling out for a new cup when I haven't had mine for that long makes me angry.
EDIT: Thanks for the advice, ladies! I ran to Whole Foods on my lunch hour and bought a size 2. I trimmed the stem in my cubicle (stealthy!) and I'm wearing it now. It went in just fine. The only difference is that the size one used to spin around really easily, and this one takes more effort. I think that means it fits me better. YAY! So, ladies under 30..don't fear the big cup!