I've been using a cup for about 7 months now, and I've noticed something..... my cervix moves all over the place! Sometimes its on the anterior (belly side) of my vagina, sometimes at the very end, and sometimes on the posterior wall. It doesn't seem to relate to the day of my cycle or anything I can figure out. I just have to make sure that once I place my cup I check around the rim to make sure the cervix is inside!!