Negotiating an offer, is it too late? - what worked for you?

I received an offer as a quality inspector and I think the pay is a little low. This is my first time dealing with any of this. The hiring manager was friendly and open. What wording worked?

If they say no, consider asking for something else, such as a review in six months.

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