Me: age 46, no pregnancies, not a virgin, retroverted uterus, very heavy flow for most of my period. I think my cervix is about 2.5 inches (6.5 mm) up, based on some checking I did towards the end of my last period. Having used tampons and diaphragms, I'm very comfortable getting things in and out of my vagina. I've wondered if I have lax PC muscles but base that only on the fact that most of the time, tampons seem to slide out of me no matter how far up I position them. (I've been trying to do kegels every time I'm stopped at a red light while driving...which in my part of the world, is pretty often.) I can often feel tampons poking me...not sure whether that relates to PC muscles or an extra-sensitive vag. In terms of brand availability, I live in the U.S.
So for my first question, What makes a cervix "high" versus "low? I don't know whether my measurements translate into being "high" or "low." Or should I wait until my next period and check the distance when I first start to bleed?
I guess my next question is, Given the information I listed about myself, do any brands jump out as more likely to be worth trying, or more likely to be wrong for me? Does my experience with tampons sliding out and/or poking me internally, make it less likely that I'll be able to use a cup?
Thank you so much for the help! I understand that this can be a trial-and-error process but thought that the collective wisdom here might save me some mistakes.