Vaginal/ pelvic floor pain

kay

I’m 35 weeks and recently got the excessive ball out to start hip rotations. Everytime I get on for the first 5 minutes I get sharp pains in the pelvic floor. They only last a second but will happen on and for the first couple minutes that I’m on the ball. It feels like a quick stab in my cervix. I’m going to bring it up to my doctor at my appointment. Has this happened to anyone else?