What Causes Milky Discharge From Nipples Post Gall Bladder Removal?

Hi... i am female 24 yrs...on sept 10th 2015 i had my gall bladder removed because i had a gall stone of 10mm...at the time of laproscopic surgery doctor noticed 2 bile ducts(one being very small)...so as a precaution they placed a stent at that site...on december 10th i got my stent removed...before surgery on 31st aug my thyroid levels (tsh-11.1,t3-0.26,t4-9.4 method ELISA) so doc prescribed me thyronorm 50mcg. Again on 26th jan i got my thyroid checked and it shows (tsh-0.31,t3-124,t4-8.3 method C.L.I.A) every thing under normal so doc suggested me to use thyronorm 25mcg...since 4months after surgery i am noticing white or milky discharge from both the nipples when i press but my serum prolactin level is 13.3... this is normal and i am not pregnant..my serum glucose fasting and post breakfast are also normal...my GN doc suggested that everything is normal nipple discharge may be because of medicines used after surgery...prescribed domapeeidone content tab during surgery but i stopped using it after my stent is removed(10th dec) what may be the cause for my nipple discharge? Is it ok not to take any medicine for nipple discharge and let it go on its own...need your help