hi im new here, a hope a get answer on my question

im 25yrs old, a have a lump under right  arm, for almost 3years, before this, i was ckeking my self, i found a lump in my left brest, and a had a biopsy and they cleard it , doktor said it wasnt nothing series. so after that i was cheking my self again and i have found that lump under my right arm, it is soft and moving, so a asked my doktor to have a sonogram of the right breast, and i did, but they said there is nothing, and i even had a mamogram (mammogram), of my right breast, they stil say there is nothing, but a had pain under my arm and over my shoulder, so i ask my doktor again to have sonogram but he said there is nothing , i said this time i want sonogram just to seeright under the arm not the right breast, so i did have that sonogram, and for surprise, this time they said there is a lump not one but two lumps under my arm, so i got more scared,and they said its size 1cm. after that i had a went to see specialist for that, i asked him if it is a cyst, he said no, it can be only infection or cancer, and he gave me antibiotics like if it is a infection it should go away, but my lumps stayed the same  so i did use them for 10days, and again i came for check up, he said it is nothing to worry about, if lumps grow from anitibotics, they would do some action, but it stayed the same so its nothing to worry about, he said i just should come again for 6months to check up on it, but way would they tell me to come again if it is nothing, and they wont do anything if its something, i still dont know what is going on, they are not telling me something?