Ok hun I think ur ok providing it’s not hot or sore. If it’s massively different like an egg compared to a grapefruit then I would be more worrying from what I’ve researched.
To be on the safe side tho pls just contact the nurse when u get a chance and send them a pic for reassurance. I called the emergency line the night before my 7 day check up, she senr an email and I sent a pic back then she called me back.
I was worried about some sudden bruising and pains on my right boob (smaller) thought I had s blood clot coming on in my right leg and arm where I had the smaller boob. Really put my mind at rest amd my surgeon was contacted so I saw her on my 7 day check cos she was concerned too. It all made me feel really assured thank God for the emergency line!
I think it’s normal for one to be a bit bigger than the other but no harm in checking it with the nurse fxx