Are you using the larger or the smaller cup? I had issues getting my Diva to open and I'd ordered the larger size based on my age (37). I downsized and used the triangle fold and it was easy to get it to open. Even with the smaller size cup the punchdown or C/U fold don't work for me, they won't open.

Every 4 hours is heavy but not alarmingly so unless it's unusual for you. The good thing about cups is that many of them (Diva too?) have little measuring lines. Write down how much you bleed each day and tally it up. That is good quantitative information to give your Doctor.

Maybe you're just having a bad period. They happen sometimes. But if it's a sudden change, it's worth mentioning. Similarly if it regularly alternates heavy-light from period to period.

It could just be a natural change. Or it could be something like fibroids -- which are more of an annoyance than anything (quote-unquote) "wrong." However, they could interfere with having children if/when you're ready.

Try enlarging the anti-suction holes on your Diva. They're notoriously teeny. And skim/read http://kuradi8.livejournal.com/ for other helpful hints.

Thanks for the info!