Thanks everyone for all the lovely messages.
Well today we saw the oncologist and discussed options. Chemo isn't used for this type of cancer as it's not been shown to be effective, but the melanoma vaccine could, assuming the cancer hasn't spread, give her up to 4 years, which is amazing.
But he found a pea-sized lump on the internal part of her wound and because it was close to where there's a lymph node, he wanted to check it out.
20mins later he came back and his face had completely fallen - the lump is fatty scar tissue but has some abnormal looking cells which may or may not be cancerous. He's sending the sample to an expert cell person to confirm either way, but if the cells are cancerous then it's likely that she will have cancer elsewhere, esp given how quickly it means it'll have grown back (the tumour only came out two and a half weeks ago).
If it's as we fear, then even with the vaccine we're looking at probably 3-4 months.
He also said that her pale gums could be down to excessive blood loss during the surgery, or could be down to the cancer, or both.
Either way she isn't herself. We took her to Shoreham on the way back, her favourite walk (had a COL meet there some time back), and she tried to perk up but couldn't really manage it - normally her and Zorro go totally loopy on that walk but it was just Zorro bombing around on his own.
We should get the results from this new lump tomorrow or Monday - the vet didn't want to discuss anything else until we have that.
So a very emotional day really. My gut feeling is it will be bad news but you never know...