So starting Monday out of nowhere and after a whole day of light outdoor activities I noticed there was a big spot of blood on my underwear (not enough to leak through though), and this happened the second day and now I have been lightly bleeding (less than those two days) for 5 days. I was not that concerned about those two days because I noticed this past year that if I engaged in physical activities I tend to bleed but they go away in three days. Now I am really concerned because my back is hurting. I was hoping my back was hurting due to the fact that on the second day, as silly as this sounds, I was shaking my hips  as I danced to music and also the fact I injured a nerve two years ago so my back has never been the same. The day before I did have a migraine or a tension headache (cannot tell the difference) and took tyelnol. Morning of symptoms was normal. Other than bleeding and muscle pain in back I do not feel anything. I am 17 and not sexually active either.