My 2nd pregnancy and again a cyst in my left breast no pain the radiologist said it is nothing bad just fluid or just maybe milk could it be possible?

Yes: If the radiologist did an ultrasound and it showed a simple cyst, i would not be worried. If painful, it can easily be aspirated with minor discomfort.

Yes, it is possible: Some women may find a lump appear around the second trimester.The most common ones are cysts (fluid filled sacs), galactoceles (milk filled cysts) & fibroadenomas (fibrous tissue). If you already have a fibroadenoma it may get bigger during pregnancy. The vast majority of breast lumps in pregnancy are benign (not cancer). However, it's a good idea to get any new breast lump checked out by your dr.