I have been on the pill for about 2 years, and have had mostly regular periods without missing any, but my last one was only old, brown blood and very very light. I took two pregnancy tests and both came back negative. I am wondering what else could cause me not really having a period?
The hormone levels in the pill are quite low so it does happen commonly that women may have minimal bleeding at times because of the thin endometrial lining from low hormone levels, and it can vary due to stress or other hormonal factors. Some women have no period at all. Of course there may be a very low risk of pregnancy even if you are taking your pills properly, but you have checked for that. It still can cause some anxiety if you are used to having regular periods.
This is not a problem based on the long term studies of women on oral contraceptives. If you continue to have very light or no periods, talk to your provider about whether a change in pill would be indicated.