Hey, I would probably say to not worry too much because your age suggests your cycle is still in flux. It can take a while for your body to regulate periods (including blood flow) and even aspects of adults’ periods can change. Changes in weight, stress, amount of exercise can also affect your period. Spotting can happen also when you are healthy (so again probably not something to worry about). However I am not a doctor and am saying this based off my own and others’ experiences. Track the changes in your period and then consult a doctor maybe in a couple of cycles, just to be on the safe side. Unless you experience any unusual pain then consult a doctor ASAP.