Would I have still received Whatsapp messages if I had the iMessage button switched off in Settings on my iPhone 5?

For some reason, I got a notification telling me that iMessage wasn't enabled, and gave me the option to enable it. I have no idea why it wasn't enabled already? But I'm concerned that iMessage being switched off would have interfered with receiving Whatsapp messages, as I use Whatsapp a lot.
I'm not very good at technology. I'm thinking that both iMessage and Whatsapp use internet for the messaging, and maybe having the iMessage off would affect Whatsapp too.
My brother tells me that it wouldn't be affected, but I'm just wanting to be sure. Any answers or help would be greatly appreciated, thank you.

No, 2 completely different things. They don't interfere with each other