Common topic - breast pain

Hi

I had a screening mammogram end of jan that was clear (but also came back saying heterogeneously dense which I know near to 50% of women have). I am almost 42 yo.I had some shooting pains round my armpit under and sometimes to the back but moving around. I had been having them for a month of so before my mammogram.
I went to the GP just to get her opinion and she said she was not too concerned. Checked the breast and armpit and says everything was a bit lumpy (related to menstrual cycle) but she did not feel anything of concern. She says to check back in with her assistant in 2 weeks. In those 2 weeks my breasts got very sore and sensitive which was due to my cycle (I
am on the mirena so difficult to pinpoint it exactly other than breast soreness) . Then things calmed down but I still had the random shooting pains from time to time. Mostly around the armpit and sometimes in the shoulder so she said probably muscular skeletal.
So away I went but then my breasts get sore again and the right it sorer than the left. It is also smaller than the left. So of course I have been I obsessively checking and there feels like lots of lumps (I assuming just breast tissue) nothing super hard though. The right one feels ‘firmer’ than the left but I wonder if that is because it is smaller than the left. Does anyone else feel this difference between the two because of size difference ? I am
Thinking it might be because the tissue is nearer to the surface on smaller breast and less fatty ?

When we talk about pain coming and going do you mean pain thst is shooting a few times a day or when you have no shooting pains for several days and then it comes back. I have it in both breasts but far more frequently on right.

I am not sure if I am obsessing over nothing or if I should go back ?

When I read a mammogram is not as effective in dense tissue I lost a bit of my confidence in it and wonder if I should ask for an ultrasound to put my mind at rest ?

Well done if you have managed to get to the bottom of the novel but I wanted to put it all in here. Thank you for reading. Grateful for any viewpoints.

Just checked my report and it was a 3D mammogram which I believe is better at detecting in denser breasts so that makes me a bit happier !

Hiyer, sorry you didn't get any replies, and this was quite a few days ago you posted...... how are you feeling about it now ? Have you considered, that if it is the 'larger breast' (which of course is very common in many people) that something about your bra fitting could be incorrect ? Or an underwirde bra is causing problems ? or something about your posture or some repetitive movement on that side is affecting it ? Its worth thinking about, as pains that come and go and get better and worse would certainly not point to anything sinister. Also, the 3D mammogram is an ace tool, I think that should be really reassuring - I've never had a 3D and I'm on a yearly mammo programme.