nail melanoma – false negative?

Hi everyone, recently I went to a podiatrist and he performed a 4mm punch biopsy on the second toe of my left foot to diagnose nail melanoma (had a black line in the middle and feint brownish bands that cover the black line for about 2 years). I really thought he knows what he was doing and I was hoping that he used a nail spatula to reflect the nail fold and collect the tissue sample (pigmented lesion) from the now exposed nail matrix but after I got home and looked at the toe, he actually did the punch biopsy on/over the proximal nail fold after nail avulsion. He also confirmed that with me. The pathology report says the tissue sample was: skin (4mm x 3mm x 2mm) and the diagnosis was :benign acral melanosis.” Since it was only 2mm thick, I’m not sure if the punch tool was able to collect tissues from nail matrix (where subungal melanoma originates). I read from this website, https://www.mdedge.com/dermatology/article/150656/dermatologic-surgery/nail-biopsies-made-simple and is says, ““Do not use a punch biopsy on the nail fold to diagnose melanoma – you will get a false negative,” Dr. Skelsey said.” I really don’t know if the podiatrist got the tissue sample from the the nail matrix or not. It seems this doctor wasn’t qualified for nail matrix biopsy? I called him and he said “since you have doubts, best thing to do is get another biopsy.” It has been about a month since the biopsy and he wants another biopsy. I don’t think the nail matrix is fully healed. I wonder if the pigmented lesion in the nail matrix is still there? I don’t have health insurance and I already paid him and the pathologist a lot of money for perhaps, a botched biopsy 🙁 Maybe, the pathologist was looking at the tissues from the nail fold hence, it was a false negative? So worried right now. If I want a second opinion, how long do I have to wait before I can have another biopsy? Thanks for any input. I’d really appreciate it.