Has anybody ever experienced this?

I've recently noticed a dull pain in my right breast. It's like a mild throbbing pain and not constant, there also feels as though there's something there at the outer side of my breast going towards my armpit. I have thoroughly checked myself for lumps and there is nothing whatsoever that I can feel and I've gone in pretty hard to be extra sure. I have no breast changes in size or shape, no changes to my nipple and no other signs that I should find alarming, I do have a shoulder impingement at the moment in my arm on that same side so I wonder if it could be related to that? Or if its a menstrual thing because I'm on cycle day 1 today and this started around 2 weeks ago I'd say, but it could have been longer. And I've noticed the past few days that when I take my bra off I notice it more. I do have a bit of health anxiety so obviously I've been consulting Google and I'm getting mixed info. The NHS website for the UK (where I'm from) says that breast pain like this is not usually cause for concern but my health anxiety makes me think the worst. I have a doctors appointment tomorrow to get my cortisone injection for my shoulder so I'll ask her to examine me to put my mind at rest.

But I just wanted to know if anyone else has ever had this happen before? I'd feel better knowing I'm not the only one

Definitely not pregnant lol. I'm on my period and haven't had sex recently so thats out of the equation. But I went to the doctor and she said its linked to my shoulder pain, the pain can radiate so I'm relieved!