What could this be?

[Chipsandchicken]

Doesn't look as bad on this picture but this morning 4 year old ds has woke up with what looks like a lovebite on his neck! Picture not showing how bad it actually looks. Does anyone have any idea? Purple spots/marks?

I sometimes get a small bruise like that under my chin caused by my cycle helmet, but that looks more like it's on the side near a shoulder?

It's a lot higher than his shoulder. Exactly in the middle of his neck. Pretty much where you would find a live bite is only way to describe it. I don't know why but for some reason it's actually quite worrying me

Mark from the car seatbelt/car seat strap maybe? What are you worried it might be?

If he's well in himself, and other marks don't start popping up, this really wouldn't worry me (and I like to worry!).
As others have said it could be a pinch or bruise from something - does he carry a rucksack, wear a seat belt? Could it be from the zip on a coat or hoodie?