I have a copper t that i know is in place as i just went for a pap smear. my period is 3 days late with a negative pregnancy test. whats wrong?

Late period: A urine ("home") pregnancy test can be negative at this point. If your period does not occur in the next week, obtain a serum HCG test (much more accurate). Your period may be delayed secondary to a delay in ovulation, which begins to be more common in one's mid thirties on. IUD's , especially the "copper T" are excellent for birth control, but not 100%.