For me It looks like the beginning of vertex and crown thinning. Don't panic, get on finasteride or dutasteride asap. You have a good density as I can see. But you can lose it before you turn 20. Don't do my mistakes. At 21 I noticed a little spot on my vertex that I never seen before. I hadn't thought much about it until the day when my agressive thinning started. When I turned 22 I lost nearly 50-60% of hair density all over my head. I always had very thick hair, so now I am looking just like an average guy. My current regimen is finasteride 1.25 mg/eod and dutasteride 0.5 mg 2x/week. I use it in hope to prevent further loss and hairline receding and of course to get some regrowth. I started recently so there are nothing to say about my progress. I don't have a history of male pattern baldness in my family, just moderate hairloss in my father's brother, but I don't look like him at all. So I tend to think in my case it's a telogen effluvium due to high stress and poor diet. But in your you should be very careful, cause your dad is bald. Just one important thing you should know: you can prevent further damage only with meds if you genetically predisposed to mbp. Just keep in mind that time is not on your side in this problem.
