The key word in your post is...muscle. Fibro affects the muscles, tendons and ligaments. If you have strained them, overdone things, etc., this can cause the muscles to tighten. I'll have days where I'm very "tight" and it hurts to move.
You might try massaging your abdomen. As far as the chest involvement, you could have costochondritis, too. I have that and that ibuprofen for it. There is a link in Fibro 101 about costo.
Sherrine