Thanks for your query,
Feeling of some type of movements inside the abdomen may be due to passage of materials (solid or gas) inside the intestine. These are known as "Phantom fetal kicks ". They may occur due to gas or may be even worms. False pregnancy
signs and symptoms (Phantom pregnancy or pseudocyesis) may occur in women who are highly desirous of pregnancy but unable to become pregnant . This occurs due to psychological cause.
Your pregnancy test is negative, it means you are not pregnant. You may get checked by a general physician for your problem.
Take care and best of luck..
Hope it helps you..