What does it mean when you piss and little bloody tissue comes out and stings to go?

Lately my stomach has been hurting and when I go use the restroom it stings to piss, plus some little bloody tissue comes out. I don't quite remember how many days it has been but it's recent. I've done some research and I'm getting the feeling either I've got something wrong with my bladder, kidney, or it's a uti. The only thing is I read the some of the symptoms and my pee doesn't smell and the pain in my lower stomach doesn't hurt that bad (yet). The blood tissue is very small, almost reminds me of spotting like on periods. Which that's another thing, I last had my period last month. I think I might miss mine for this month due to stress yet again it might come later in the month seeing how I have an irregular period....Oh! I forgot to mention I've had this pain in pee before but it was mild and it only happened when I had too much..ehm, kinky sex with my fiance in the past. Though it went away over time to let my body heal itself through taking hot baths and staying in bed. Now it's different, today I felt a bit nauseated (sorry if mispelled it) and not so hungry lately. I think it's just due to my weird timming of eating since I haven't been sleeping like most people do (I normally sleep at day and awake at night). Anyways I'm sorry I ranted so much. I just thought maybe someone here will be able to help me. I don't want to go see a doctor right now because financially I can't afford to and I don't want to worry anyone.