You've got the hairline of a 14 year old girl
It sure doesn't look like anything more than a mature hairline. But, do you have a "hole" in the back of your head too? Then it could be the earliest sign. Mine started in my mid-twenties, just "pulled" back in front, but a hole in the back too. That grew and the front thinned out over the next 10 years, then stopped for a while. Note: I tried minoxidil at first on the hole, but it wasn't for me, no hair but a hell of a rash for several months that made money for the dematologist. Someplace on the web is a chart of MPB, if you have a hole, try to find it because you will gain some understanding of what's going on.