Kidney pain or menstrual cramps?

K

I started my period this morning. I was having bad cramps so I took a pamprin. The cramps are still pretty bad and I'm also having a really sharp pain in the right side of my back, not in my lower or upper back but more so right under the ribs. It's pretty bad and I have to work tonight so I'm a bit worried. The placement makes me think it's kidney pain, could it be nothing to worry about?