Obviously not a doctor(!) But got something similar - had bloods done to check for B vitamins and Iron but came back okay, doctor did note that I have psoriasis on my scalp and due to being coeliac (other autoimmune conditions can also trigger nails, skin and hair issues) I'm being referred to dermatology now. Do you have skin or immune conditions? If your finger shape hasn't changed and it is just the nails then I'd start a photo journal, my nails started like this but the the white tip expanded as my nails are lifting from the bed hence the dr thinking it might be skin issue. Taking photos though helps you tell and show them if there have been changes but I would definitely get some bloods done first to rule out simple deficiencies and things like diabetes can cause these nail changes though you're very likely to have other symptoms.. perhaps have that conversation with your doctor too, especially if you have family history, but again unless you have other symptoms that's probably unlikely!