New user- questions: menstrual_cups

I am so glad I found this forum, it has so much good info. I just got a Diva Cup(model 2, I'm 33 and have had 3 c-sections) and Insteads and used them both with varying success yesterday and today. I have a pretty heavy flow on day 1-2 which I think caused some of the issues yesterday. I usually wear Super Plus ob tampons and change them every 3 hrs. on Day 1. So I thought I'd be able to wear the Diva longer than that but yesterday after 2 hrs. I went to the bathroom to pee and while peeing I saw a few drops of blood fall into the toilet so I decided to check the cup. It was filled to the upper line-15ml I think. Is that normal? That was my pattern for the rest of the day- every 2-3 hrs I'd go check for leaks/spotting and there was always at least a drop or two of blood on the toilet paper or usually more (sometimes I'd pee first and sometimes not) so I'd remove and it was always filled above the bottom line and usually closer to the top line(and that was with quite a bit of spillage going on). I am fairly sure I was getting the placement ok- couldn't feel it inside, could turn the cup or run a finger around and it was fully open and seemed sealed well, found my cervix and aimed that way-it seemed to be inside the cup. I was concerned that I was wearing it too low after seeing how many people talked about wearing it higher but I can't get it in any farther! I trimmed the stem a bit and it doesn't poke me or bother me but if I look with a mirror I can see the stem right inside my opening. I can push the cup out pretty easily with my muscles but doing kegels and wiggling, shoving does nothing to make it go farther in. It doesn't hurt to push it but it just won't go anywhere. Does this mean I just have a shorter canal than some people?
Is it possible to remove a half full or more Diva cup without a huge mess? I have to pinch/fold the cup when I'm removing it for comfort(first time it popped out at full size and yowza it hurt!) and the blood just gushes out. Not a big deal at home but no way could I do this in a public restroom.
I had similar removal issues with the Instead but even worse. I was peeing and all of a sudden-gush. I quickly removed it but the baggie was flattened and practically empty. How can you keep the bag from being squeezed/flattened when you remove it? I was keeping it level and steady but it still made a mess. And does urinating cause your muscles to bear down enough to break the seal on a Diva(hence the leakage I experienced) or pop an Instead out of place? I did not have any spotting on my pantyliner at all yesterday or today so I don't think I was having true leakage issues. Today my flow has lessened and I've had less problems but I would like to know if this all sounds like normal heavy flow issues that will always happen or if it sounds like I was doing something wrong? Thanks for any comments/advice.

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