I don't think I would worry about IBC. I don't think that presents with a lump. From my understanding, you would have a rash all over your breast and it would swell almost overnight. My friend, who is a breast radiologist, told me that an IBC rash generally affects the entire breast, not just one spot (but you don't even have a rash - so don't worry!) I have had breast cysts all my life and they can hurt - and they can hurt in areas that are in a different spot - I would assume it has to do with the nerves in your breast. Breast cancer usually does not present with pain. You are smart to get an ultrasound - if it is a cyst then you an have it aspirated right then and there. Then the pain will be gone!