Should I suspect hair loss if my parting seems to be getting wider?

Lately, whenever I tie my hair up, it feels like my parting is more distinct than before.

It's not like I'm losing a lot of hair, but
When I take photos, the top of my head looks thinner than before, so it bothers me.

I wonder if it looks that way because of the lighting.
It was difficult to tell on my own whether my hair had actually thinned out.

For those of you who have undergone a hair loss test due to a change in your parting, I would like to hear about your experiences regarding what tests you underwent initially.