Offer arrived, can I still ask for more? (Omaha)

It is the first offer in 5 months and I do not want to mess it up. There are 13 people counting on me, so I am trying to be careful. The hiring manager was friendly and open. Did it backfire?

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

Most employers expect a short conversation. Mine did not even blink.