What Causes Spots On Breast?

hello I have a question I have a spot on my boob it s like a hard night in the sidelines like its right beside my nipple its inside of my boobs I was like it first came there when I was 5 months pregnant my baby is 4 months now and well it\ s happened its like when its like when away came back when I wake up at like several times okay well when it first did it I went to the ER and it is like busted open and it was like a whole went to the ER they like clean it out everything and you note example well they couldn\ t tell what it was so they had sent me to a pain specialist well then the booze specialist said that they should have never cut it open he can\ t do nothing about it you can\ t look at it or whatever so I came back home and I just cleaned it and you know I\ ll let it go away on its own well this is happened about I say maybe 6 or 7 times now and it like alternators like my right boob is like in the summer Nubiles same place it\ ll get really hard and really really painful like to the touch painful and then when its like gets so like to a certain extent be then it comes back to the other boots and a bus doesn\ t like it always comes back to my left boob when I\ m going to bust but it like alternator back and forth its but its never busted on the right one I\ ve never heard of this and I was just wondering if somebody could tell me if maybe of what it could be please get back with me