I would say actually it's not normal. I always lost a lot of hair all the time every day since I was a kid and always assumed it was "normal". I believed I had begun balding at 25 or so, because that's when I really saw the frontal straight hairline start to curve back. But in actual fact, I had probably been losing hair very slowly since my teens (hairline "maturation") where I was losing my NW0 and going into a NW1 with thinner and farther back temple points. In truth, this has likely represented a slow gradual movement into my "hair loss years" where I went from NW1 to NW2+ or so over the next ~10 years from 25 onward.
With very gradual hair loss, it is easy to convince yourself the shedding is "natural".
However, once I got on aggressive treatments and they had a few months to get past the early Telogen Effluvium phase, my hair no longer started falling out at all.
I am sure I lose hair sometimes still - I must. But I almost never see it. I used to see 20+ hairs in the sink after applying RU. Now when I apply daro, i might get one hair come out in the sink at most. When I showered, I used to have to wash hairs off my hands periodically during the shower. Now, again, maybe 4-5 at most will come out in the shower (and I am rough) if I am showering daily. There are also no hairs on my pillow and I toss and turn a lot.
So it is hard to estimate just how low it is possible to shed until you get on a good therapy. And it's easy to downplay shedding as "normal". OP your hairline looks like it's moving towards an early NW2. The most important question would be whether or not your corners are farther back than they used to be a year or two previously. If they are, and you're noticing increased shedding, then consider watching it a bit longer, and if it continues to move back or shedding increases, start treatment.