Negitive pregnancy test still 12 days late on my period. What's wrong.? Ii'm still having signs and cramps..

Missed period. Missed periods are not unusual, and it sounds like you missed one if your test is negative. Home pregnancy tests are very accurate.
Ovulation. Most of the time, this indicates that ovulation did not occur and the menstrual period may be late or skipped altogether. Occasionally a cyst develops on the ovary that does not resolve or may bleed within the ovary and cause cramps. The signs and symptoms are from hormone production by the ovary. If a cyst develops, they resolve about 97% of the time. If not resolved, may require treatment.