Hi I Have Been On My Period For 5 Days

Hi I have been on my period for 5 days now extremely light to where I really don't have to worry about a pad but here lately I have noticed a blood clot about the size of a nickel with white stuff in it I have had this happen three times now and my monthly is still extremely light have gone without a monthly a little over a year due to getting the depo shot should I be worried or could it be from not having a monthly in so long