Period came back after 2 days?

I got my period 8 days ago, it lasted the usual 4 days but I would say it was heavier than normal. I had 2 days period free and suddenly I’m bleeding again? I am not on birth control, haven’t had sex and haven’t ever experienced this before. It would be more accurately described as spotting I guess, it’s very light. I’m just really confused and it’s making me feel a bit anxious. I have recently been diagnosed with anorexia and honestly haven’t eaten very much at all over the past week and I know this can affect my periods but I thought it would be the other way around and make me stop/have lighter periods. It could also be totally unrelated. Does anyone have any ideas what could be causing this?