Thin hair on crown - am I losing hair? (Pictures included)

[Dannyboy90]

26 years old Asian - just noticed that the hair on my crown is thinning. Can you advise from the pictures if I'm losing hair? My hairline seems alright and my family (both paternal and maternal) has no history of hair loss. Could it hair loss or some other factors like lifestyle, hair type or stress? Please advise!! Thank you for your help.