I tend to get UTI's when using my DivaCup for more than a few days. I'm EXTREMELY prone to them though, and so my NP thinks maybe the DC is not for me. But I really do like my DC, so I've just been taking Macrobid (which I always have to take after sex) during my period which has helped. Precautionary antibiotics > tampons, in my opinion.

It should be fine, just sharing my UTI/DC experience, although not completely related to your situation. :)