I quit smoking cold turkey 3-7-13. i had a slightly irregular period 2-3-13 (lighter, shorter). i haven't had a period since, negative hpt. related?

Maybe: There's no telling what will happen to the brain and its functions, including regulating the cycle, when a person stops smoking as you did. However, i could find nothing in the medical literature to support this, and perhaps you & your physician can seek the cause elsewhere if this persists. Mostly, i simply wanted to congratulate you. Stay physically fit and eat healthy; i bet the cycle resumes.