It stopped after it got warm. When I left out home, it was quiet(Quiet enough that me and my dad wondered if it had died again), and when I came back, quiet.
I seriously hope it's nothing bad, as I'm like, already gathering parts for a top swap...
Ah also, oil is 5w-30
Edit:
Didn't do it again when I started it on to go somewhere tonight, was all good it seems.