okay so I usually get my periods at the end of the month. I'm pretty irregular and don't keep track of them like I should. towards the end of jan I started getting a dark brown blood flow instead of a regular color. it wasn't light but it wasn't as heavy as a normal period. this happened for about a week, stopped, then happened again two weeks later. I havent had a period since then, probably due to the stress and worry I've been having over this. I haven't had sex so I can't possibly be pregnant. so what could it be

It happened the same to me in a period of great stress. When I calmed down it went away, but I also checked with my doctor and that helped me to calm down too. I suggest to check with your doc too, he can help you give something against stress and also see if there is not something wrong. All the best.