pinning drawing injecting

I must admit, when I was about to inject for the very first time a couple of weeks ago I was shaking like a 12 year old girl. I wasn't scared of the needle, more of hitting the sciatic nerve in my glute, which you WILL know about if you do. I've seen a lot of new guys asking how to pin on a lot...

Do most of you guys change out the needle after you draw and before you inject? That's what I've been doing, but I hate losing the oil that's in the needle. Wondering if there is a popular opinion here one way or the other.