Vaginal itching is a common complaint in your women. This could represent a condition that requires medical attention. I would recommend you discuss this with your primary care doctor
or ob/gyn to further evaluate this.
In general, vaginal itching is a common symptom of a condition called vaginitis. Vaginitis is a term that refers to inflammation of the vagina's inner lining (the vaginal mucosa). There are many possible causes of vaginitis. The three most common are (1) bacterial vaginosis-a change in the bacteria in the vagina that requires antibiotics (2) a yeast infection--requires anti-fungals and (3) trichomonas - a sexually transmitted disease that requires antibiotics. These often are associated with vaginal discharge or a bad odor--but this is not always present. Other causes of vaginal itching are sexually transmitted diseases like herpes, chlamydia, gonorrhea and even urinary tract infections can sometimes cause it. These should be ruled out.
There are many changes that occur in the uterus and vagina during the cycle. There can also be changes in the vaginal mucosa that are associated with changes in the hormones. These changes can make you more susceptible to the above vaginitis causes, but may also cause problems.
I would recommend seeing your doctor. You should have the vaginitis causes ruled out. If these are not the case then you should discuss further options with your ob/gyn.