Found lump in armpit - waiting for ultrasound

Hi everyone

This is my first post. I'm 31F and found a lump in my right armpit nearly 2 weeks ago. There's an obvious visible "bump" compared to my left armpit and I can feel a small hard "something" inside, a little larger than a big pea. I was due for a physical so I made an appointment right away with my doctor to get it checked out (had to wait a week before I could get in). It seemed like the doc had a hard time feeling it (not sure why, since it's fairly obvious to me and anyone else that has looked at it - boyfriend, sister, mom) but she said it could be an axillary node or just muscle (?). She did give me a requisition for an ultrasound though since I have a family hx of bc. No mammogram as I suppose I am still on the young side for that? The ultrasound is scheduled for Monday (another week wait since the doc appointment).

I haven't been too concerned since I know the odds are in my favour that it's something harmless, but today I've been experiencing on and off short stabbing pains in the side of my right breast. It could very well be all in my head, but something is starting to feel a bit "off" to me - that area seems to be more tender to touch today. It did not hurt at my doctor's appointment though and she didn't find anything noteworthy during her breast exam. I am eager to have the ultrasound in a couple of days & results shortly after that to hopefully put my mind at ease!

xo to everyone else waiting for results too, may you all hear good news.