Offer arrived, can I still ask for more? - first time posting

I received an offer as a medical assistant and I think the pay is a little low. I have read a lot of threads here and could not find my exact situation. The benefits are decent. Did it backfire?

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

Thanks for writing this out. I went through something close to it 14 months ago, and it settled down once I kept a simple log of every call and form.