period cramps

is it normal to a. stop bleeding in the middle of a cycle and b. have excruciating abdomen pain? my period has never gave me cramps this bad, and I know that they change, but this is too much. the pain moves up from my lower to upper stomach. as I'm typing this, I'm curled up in a ball under the coffee table in the living room. also, how do I explain to my mother that this is more than just "period pain"?