I had a surgery(appendix) first of july and since that i do not have a period .my last period was on june 22..i have pcos but my period was regular?

Not unusual: Its not unusual after stress, including surgery, to have an interruption of regular periods. Need to consider pregnancy as well. A negative pregnancy test and no abdominal pain would make another month of wait and see reasonable. After that, you might want to see the doctor who diagnosed you with PCOS. If you do finally get a period, it won't likely be normal and may require treatment.