My periods are usually like clockwork. i have changed alot during the month (diet& i am on a lot of new supplements(natural)) i experienced spotting(pink to brown discharge) for a week in the middle of my cycle this month. i have no other symptom

That can happen: A big change in environment can alter one's hormonal balance and change the timing of a cycle or two, but of course, these changes are not predictable. Things that can influence hormones may include the number of daylight hours, amount of emotional stress, amount of physical work compared to sleep and rest, amounts and types of food eaten, etc..., but cycle changes could also be just coincidental.