Oh man. Kinda wish I knew why noses even bled, to be honest, it's weird when suddenly you see a bunch of blood coming out of your nostrils. 8I Usually because your nose is dry, though, I think. Doesn't mean you pour a bunch of water down there, but.
But anyway, if this happens again, here's a technique I heard a long time ago... I forgot it a lot, but I think it's like this: You just tilt your head back a little bit. Not too much, I don't think. And if that doesn't work, the technique might be that you tilt your head /forward/ a bit? I'm pretty sure it's the first. Either way, I hope it helps a little bit in the future. ;u;