Lower Stomach Pain...NEED HELP?

since late november i been having lower right side stomach pain. its only on the right side its a little lower then the belly on to the right, i guess u can say its in the spot of the appendix. i got a ultrasound back in dec to check for appendicitis, it came back negative for that and negative for gallstones. the pain only is felt when i push in, no rebound pain, not tender at all. im just scared its appendicitis. its been like this now for 5 months. my gastro guy said its prob ibs. im not in dying pain i just get really nervous that its appendicitis and i need surgery. i havent been to the dr in like a month or so for this. i work out everyday without problems, the only time i feel problems is when i go running it starts to cramp up and sometimes when im really full i push and it cramps throughout my stomach. do u think this is appendicitis im freaking out i need help. im 23yr male no pervous problems. do u think this is crohns? no blood in stools. what should i do next?