21 weeks pregnant and had lower right abdominal pain it felt like a charlie horse wnat is this?

I got up this morning to pee and when I got off the toliet I had. A very Sharp pain in lower right quadrant of my abdomin it felt like a Charlie horse like a muscle cramp but it hurt so bad I didn't even wanna walk the pain lasted for about 3 min then went away. Amy Idea what this could be?