Darkened skin on lower stomach.

Hello! 23 year old female here. I wasn't exactly sure what to categorize this question as so I apologize if it is in the wrong spot.

I woke up with a darkened patch of skin on my stomach. I thought it was a bed/pressure mark but I've been up and around for a bit and it hasn't gone away.

I played a softball game this weekend and did some celebrating afterwards but I'm active on a normal basis and have had worse nightly shenanigans. I've included a link to a picture of it (http://s1272.photobucket.com/albums/y392/SKB790/?action=view&current=IMG_4312_zps2f69fead.jpg). Thanks!

[JGOODMAN]

I think it looks like a pressure mark also - I don't know how long it hung around - but if it's not gone by the end of the day, it can't hurt to have it looked at .... I usually only go to the doctor if it's itchy, painful, or doesn't go away or if it becomes inflamed...