What Causes Blood Discharge During Urination?

Hello I am a 24 year old female and for the past 3 days I've noticed that when i wipe after urinating there is a lot of blood on the paper. I know it is not my period as I had it two weeks ago and the blood is only present when I wipe. It is really worrying me now. I also have mild pain on the right lower side of my stomach that goes to the middle.