Dimple in underarm

Hi there, around 6 weeks ago I had a dimple appear in my underarm and I've been taking pics (mum had breast cancer and has melanoma) and it appears to have grown/got deeper slightly

I have been to the doctors and she was very dismissive saying no lump so fine (mum had no lumps just inverted nipple) so I'm wondering if I should get a second opinion or just go with what the Dr said?

Thanku xx