Is there a possibilty that the position of a cervix may vary from month to month?
I often have problems with placing my cup (I have a lunette) in the right position on my first day of my period. On my first day I often have leaking problems. But there are also months that I don't have any problems at all on my first day of my period. On the second, third fourth and last day of my period everything works fine. The cup is in the right place and I don't have any leaking problems.
I find it a bit frustrating that sometimes I don't have any problems and sometimes I do. Leaking sux :(