Idk what a contraction feels like

Hey everyone. So I'm 37 weeks and 3 days, tonight I have been getting some serious pains along with baby boys movements. I can see my whole stomach shift and immediately after get Charlie horse pains through the back of my butt cheek, inner thigh and lower abdomen. Idk what this is , maybe he is on a nerve , or could it be contractions ? It's not a tolerable pain it's stops me in my tracks and I can't speak or move when they happen. Does anyone know if baby tends to be active before labor?