I've seen people going bald on the back of their head and it looked way different, it was more widespread and the hair was thinning. You just got a spot that is a bit less haired. Don't worry too much over it, I looked into hair stuff a lot since I am NW3 myself.
If you notice in the next months that you really go bald, you could start finasteride or similar treatment. Most things won't help when you loose hair at the temples but balding at the back of the head can be fixed more or less with good results. Also take a look at your father and your mothers side grandfather. I am not 100% sure but you usually get the hair genetics if your mothers father.
Also pls don't use Panthrix or Regaine it's a fucking scam. Never saw anyone having any decent results. Amazon reviews are fake or copers.