Brown bleeding/spotting in between period

Hello, so I have been bleeding brown blood for the past 3 days, although it’s light it’s not as light as I would expect. It worries me and obviously why I’m making this post. I don’t think it implantation bleeding because there is no pink or red tone to it. It is totally brown, dark brown. I know this can be normal for old blood to come out but this has been constant light bleeding all day for the past three days. Please share what you know with me to help! Thank you!