Does severance delay my unemployment claim? - what worked for you?

I was offered severance of 18 weeks after being let go as an administrative assistant and I am unsure how it affects benefits. There are 18 people counting on me, so I am trying to be careful. I have a mortgage and need to plan. Who should I ask before signing?

Rules differ by state. I called the claims line and asked directly, then wrote down the answer and the date.