My employer gave me a bonus for moving expenses, but I don't think it's listed on my W-2. How do I know?

I received $3,500 from my employer for the purpose of moving. It came through my normal pay stub and was listed as "Bonus" on my pay stub. But my W-2 doesn't have a "P" in Box 12...should I list this $3,500 as an employer reimbursement for moving?