Uneven and lumpy breasts

So, I have always had lumpy breasts, my left one more lumpy than the other. When I went to the clinic to get prescribed birth control, the physician wanted to do an ultrasound before prescribing because of how lumpy they were and didn't want to give me anything that would affect it. The ultrasound only found a lot of tissue :/ I am supposed to go back some time this month for an update but I have noticed that my left breast has grown bigger and become really lumpy and ropey. I am only 18 and Im worried if this is bad ? 😖