Thank you very much for your question. It is a good thing that you have already spoken to your gynecologist, for if you have concerns, it is best to be evaluated by a medical professional. Pain during urination is also known as dysuria. As your gynecologist has mentioned, this may be secondary to irritation of your bladder or urethra from blood. Another common cause of pain during urination is a urinary tract infection
. This can cause irritation along your urethra. If the infection spreads further up your genitourinary tract, you may develop infection of the bladder known as cystitis. Depending on your age and other medical history, you may have uterine fibroids and these may be irritating your bladder during menstruation. Some medications can have a side effect of dysuria.
It is not possible to receive a diagnosis without being evaluated by a qualified health care provider such as a physician or urgent health center. I suggest you speak further with your gynecologist for primary care physician
if you continue to have questions or concerns. Be sure to detail your menstrual history, describe the character/onset/timing of your pain, any alleviating or aggravating factors, past medical history, and medications.