If your Gynaec problem, for which you underwent Sonography, was not "pregnancy" , then you should go ahead and get operated for gall stones. 8 mm stone will take many years to go with medical treatment , or medical treatment may fail.
If you become
pregnant and you have gall stones it will be a nightmare for you and your Obstetrician. You will be 7 months pregnant and you will develop cholelithiasis . And you will be wondering whether to get gall bladder operation done now or after delivery.