Negotiating an offer, is it too late?

I want to negotiate but I am afraid they will withdraw. This is my first time dealing with any of this. The hiring manager was friendly and open. Did you negotiate?

I thanked them and said I was excited but hoped we could talk about the pay. They came back with a bit more.

Thanks for writing this out. I went through something close to it 12 months ago, and it got easier once I kept a simple log of every call and form.