Should I worry and start treatment / Am I balding?

[Pacino23]

I've noticed my temples are thinner, in particulair the left one (this is only visible when I'm pulling my hairs backwards). I'm starting to worry and I am not sure whether this is a mature hairline (with widow peak?) or male pattern baldness. It should be noted that my temples were also thinner 6 years ago (see F6.jpg), however I am not sure whether it was as thin as now. At the crown I don't think there is any issue, I have added two photos: one regular and one with flash.

My questions are
* Mature hairline (with widow peak?) or MPB?
* If MPB:
- Which norwoord is this?
- How long before my hairline recedes significantly (when does it starts to become visible?
* What do you guys think. Should I start treatment?

Background info
- Age: 23
- Maternal grandfather: Thick hair in his 60's
- Maternal uncle: Thick hair
- Paternal grandfather: Bald in his 30/s 40s?
- Paternal uncle: bald in his early 30s
- Father: Thick hair 50s