Hi @JayMB
sorry to hear your news - there's so much to take in and decide so quickly. I was diagnosed in May last year - like you not everything was visible and after initial lumpectomy & auxiliary clearance, I had to return for a second wide excision a week later to try and get a margin. That also failed so onto a mastectomy. My surgeon supported my choice to remove both breasts as completely reasonable even though there was no changes to the right. She was very clear that even though there was no scientific evidence for the removal of the second breast many women choose it and she could understand why and supportive of that. After six moths of chemo I had bilateral mastectomy in December 2020. I have no regrets and it is relieving that I won't have to have mammograms or breast surgeries etc going forward.
Like you I was offered and intended to go with immediate DIEP flap reconstruction but after enquiring about complication/surgical return rates I decided against it. I share this because I had post surgical complications from lumpectomies which were really tough to deal with and required further hospitalisation, medication and massive impact on my family as well as myself. I was the outlier in all of that so not at all likely in your situation but it left me feeling that did not want to have more surgery (s). I found this website about aesthetic flat closure helpful in feeling at peace with my decision for double mastectomy with no recon.
https://notputtingonashirt.org It's nearly six months from surgery now and I'm comfortable with my flat, no nipple chest.
Best of luck with everything. When I was trying to decide what to do my best friend said to me 'there's no wrong decision' and that was so helpful. They are just decisions about what feels best to you at the time - you really can't get it wrong. Warm wishes, Pru