Cramping and leaking

So this is my second cycle using a cup and I absolutely love it. I use a Lena cup in the smaller size. I also have a low cervix. About 10-20 minutes after I put my cup in (almost every time I put it in) I get an intense wave of painful cramps for about 30 seconds and I leak onto a panty liner. Afterwards, I am fine all day, with leaking only once the cup overflows. Has anyone had a similar cramping and leaking problem? Does anyone know why this is happening? And any solutions?