very sharp paints in my bladder, constant need to urinate, have my period...wth?

[Kathryn]

Okay, so it all started with when i had to pee a two days ago. When i went it had burned really bad, and i had been holding it a few hours before. After that my vagina burned really bad...and a few hours after that i started to feel the burning sensation to urinate constantly. i drank some cranberry juice thinking it was a uti, and it got better for the night. I woke up the next morning fine, no burning sensations, and no burning when i peed. Later that day i started to get the sensation to pee again. But this time when i peed, it burned a littlee tiny bit, but then right after i urinated or as i was urinating i got this EXTREME sharp pain in what felt like my bladder to where my urin was leaving. When i was done (and the pain lasted about a minute after i peed) i still felt like i had to pee very bad and once in a while i would feel that sharp pain. One time i almost peed myself and i had to run to the bathroom. I layed down for a while later that night and it STARTED to go away..i woke up this morning and i don't have the burning sensation anymore, but now i only feel pain when i pee...that sharp extreme shooting pain in my bladder/vagina. I also have my period and the second day(yesterday) i noticed i was only wearing a pad, and no blood was coming out like it usualy does. But when i peed the urin was red...it seemed as if i only bled from my period when i peed. I am probaly going to a gynocologist sooner or later but can anyone help?!