I feel a pop in my upper right abdomen every time i cough, sneeze or hiccup and sometimes at certain movements but i dont feel any pain. what causes this?

With a cough or sneeze (essentially valsalva muscular activities) displacement of a prior dislocated rib can produce this "popping" sensation: with abrupt contraction of the diaphragm a rib out of articulation with this activity can move and then resettle in juxtaposition to the original articular surface on the sternum. Prior rib injury can cause this.