After a month of open acute appendix opt. the pain persists in my lower right abdomen.yesterday's usg reports are also absolutely normal.plz help?

See the surgeon: This could be post-op pain because of scar tissue. If pain persist you should go back to see the surgeon who did the surgery on you.

Most likely adhesion: Most likely you formed adhesions , causing your problem , may take few months to settle down, usg , ct will not show them unless you have intestinal obstruction, obviously your scans did not show any hernia , you will be better soon.