You had two periods in one month but each were light and were dark brown with some blood are you pregnant?

Not neccessarily. Often your cycle adjusts itself to changes in your body. Some experience changes in the occurance if you have close contact with other women such as a roommate or sisters living together-even mothers and daughters will start to find they menstruate at the same times. Are you on the pill and have skipped or changed strength? Think about what stresses good or bad are going on. If you have been pretty regular it may just mean you are adjusting to a change in your body's timing.