I have had 3 children, and my last is 8yo. i have been having movement in my lower abdomen and dont have pain?

What is it? Is it possible that my intestines move on a regular basis? Do my ovaries move when Im on my cycle? I did go to Africa in 08, do you think i have a worm or something? well i guess I have gained weight so thats not it! lol ive taken pregnancy tests and they have been negative! I so frustrated!