Hi, I am an 18 year old female who is sexually active and have lately been getting an uncomfortable, clenching feeling on the inside (bladder or vagina?) when I finish urinating. Also my urine smells strong, almost chemical like, which is worse when I drink less. Sometimes I bleed a little after sex. I went to the sexual health clinic and they tested my urine for bacteria, and said there was no infection. What could this be? Please help!