I recently found out i have pcos i was prescribed metformin er 500mg and i keep spotting is this normal?

Not unusual: Metformin seems to be quite effective at regulating menstrual periods in women with PCOS, but there is often associated mid-cycle spotting, especially in the first few months. If it is going on longer than 6 months, I suggest discussing this with your prescribing physician. Adjusting the dose or considering oral contraceptives (depending on your pregnancy goals) can be considered. Good wishes!