Most common cause of the above mentioned symptoms is urinary tract infection
. Buts since you have normal urine microscopy & culture, it is unlikely.
Other things which can lead to these symptoms are kidney
stones, bladder stones. For knowing the exact site, its important you tell me if you notice the blood staining at the beginning of micturition which is likely to be due to urethritis
or at the end of micturition which can be due to bladder causes. Also if you have pain in the inner aspect of thigh it can be due to to kidney problems.
For now you should take plenty of fluids as inadequate hydration can also result in these problems. Also get an ultrasound
of KUB region to rule out mass lesions and a gynaecological checkup to rule out genital causes as sometimes vaginal bleeding is confused with bloody urine.