You're certainly not over reacting & of course, you are sensitised from your sister's experience, but use it go to your GP to get it checked out. As you say, most breast changes turn out to be nothing serious, but only the GP/Breast Clinic can sort it out for you.
About a month ago my sister was diagnosed with BC. She has gone on to have a lumpectomy and thankfully all seems clear - they found it very early (she is in her mid 40s). Such a huge relief!
Naturally, when she was diagnosed I read up a lot and became much more aware of BC signs, symptoms etc. Also was more attentive on self checking and subsequently have (I think) found a lump. I say "think" because I don't know whether everything with my sister has just made me super paranoid/silly - I'm also relatively young (39)? The other thing is, the lump I've found is hard but does move and I believe this makes it less likely to be cancerous? The stories of people finding lumps online all make it sound like everyone was so sure it was definitely a lump whereas I'm like..."is it?". Is this uncertainty over 'lump satus' quite common? Also, does anyone have any advice on the moveable vs static side of things?
Sorry if this is a bit rambly, I guess I'm just a little worried and worked up. x