I found some information for you... if you type in "cyclical mastalgia" you should be able to find all of the information you could ever want!
Here is what I found, cyclical mastalgia defined --
"The most common type of breast pain is related to our hormones during a monthly cycle. Stimulated by the estrogen and progesterone during the second half of the cycle, the breasts swell and become more lumpy and tender. Then with a period, while the uterus sloughs off its lining, the breasts reabsorb the extra fluid instead of discharging it. At different times, often in the years before menopause, the hormones are a bit off balance and the breasts suffer more tenderness. Many women can identify when they ovulate by the sensations in their breast or nipples. For some women this may mean too little or too much estrogen, for others too little progesterone. This type of cyclic breast pain occurs in both breasts, sometimes more one-sided than another. It is often felt more in the lateral aspect where there is more breast tissue. It may differ from month to month but always gets worse before a period and then lets up with menstruation.
Cyclic breast pain can be made worse by some foods we eat or drink and some medications we take. An obvious one is caffeine, which contains a chemical called methylxanthine that causes blood vessels to dilate. This microscopic swelling can cause distention in the breasts and add to the pain. Again it doesn’t cause or lead to cancer, so a woman may want to balance her desire for coffee with the discomfort it causes in her breasts. Decaf coffee and teas have less caffeine and most sodas and chocolates do too. Excedrin has as much caffeine in one pill as a cup of coffee. Diets high in salt increase swelling by causing fluid retention, and this also puts a strain on the breast tissue.
There is some recent evidence that fatty foods, mostly animal fats, contribute to breast pain. The reason here is less clear but may have to do with the animals’ own hormones, what they have been given to eat, or the way the fat is broken down by our bodies. For some women, dairy products are the culprit. Again the exact reason is unclear. These women may have an underlying allergy to the dairy products or may be reacting again to the hormones that were fed to the cows."
If you are able to eliminate/reduce some of the factors that may make the breast pain worse, caffiene, high sodium intake and still find you are having issues,.. it can never hurt to consult your gyno. As far as what time during your cycle to see the Dr. ... this is just an educated guess, but it is best to do self-breast exams early in your cycle (counting day one as the day you start your period), because any swelling has gone down and if you do indeed have a cyst, it might be more likely to be detected.
Hope this helps!
Ok thanks a lot, will consult doc soon.....