One boob growing bigger

Hi, I'm 22 and have always had even breasts but in May I started feeling sore in my left breast especially if I touched it in certain spot and sometimes if i stretched my arm up. That's when I noticed that my left breast had grown noticeably bigger than the other. The sore spots in the breast were there for about a month but since mid-June I haven't had any pain anymore but the left breast is still very noticeably bigger and I'm worried because when you google one breast growing all that comes up is IBC. Is it possible to have IBC without any other symptoms than one breast growing? I also think I have fibrocystic breast tissue so I don't know if I have any lumps because both of my breasts have always felt "lumpy".

I want to go to a doctor to have it looked at but I just moved to London so I don't have a GP, can I go to a walk in centre with this concern or will they just tell me to go to a GP?

And my dermatologist thinks I have hormonal imbalance, is it possible that that has caused one breast to grow without affecting the other breast at all?

Thank you!

Many women have breasts that are different sizes. That said, it is indeed, always best just to get the reassurance and medical opinion from an expert. Can you perhaps establish yourself with a new general practioner fairly quickly?