I noticed that there are a lot of questions regarding brown discharge, but all that I've seen are from sexually active women... and I just want to ask to be sure, so please forgive me for rehashing this topic.

I'm 19 years old, and I've never had sexual intercourse. However, I have been making an effort to cut back on/quit masturbating, and hadn't masturbated in about a month. I don't know if that's relevant, but I want to provide as much information as possible.

Normally, my period would have begun about a week ago, although it's not terribly uncommon for me to be a week early or a week late. I've been cramping worse (although not unbearably... just a little nausia with mild to moderate cramps) than usual for about 3 days, and today I wiped after urinating and saw a brown discharge, thinking this to be the beginning of my period, I put on a pad, and checked back after a couple of hours, and it's all dark brown. No red blood to be seen yet.

If this is old blood, why is my body not releasing it right away, like it normally would during a period?
What do you think?