Suction causing bump

Hi there

I have a question regarding the suction. Recently I felt a kind of bump in my vagina. It was about the size of a acorn and hard on the inside. I was also not able to push it in, like where it came from. I took out the cup for a night and the bump was gone for the most part. There is still something hard that I feel through the vaginal wall, not sure if it could be because the cup, since it has shrunk quite a bit.

Has somebody else experience with this?