It's common practice to aspirate to make sure you're not in a vessel. Only when the drug or vitamin is either SC/IM/IV that it doesn't matter, so plunge and push. Otherwise, check first…a shot of many things IV into the heart might not be cool. There's a reason the route(s) of administration exist…they're written in the blood of dead people and animals.
That lava looks like a river now…much more on the move.