Supplementing with formula, how bad will this effect my supply?

I'm not sure if this is true, but I was told that pinching your can keep your supply coming if you can't nurse for whatever reason for a while. Just keep hand-expressing, But it shouldnt take too long to build your supply back up, just pump ALOT when you get your pump. I gave my son a bottle around 5 weeks and he had a really hard time latching on again so be careful about that.