Weight loss reward?

I've been eating healthy and working out 3-4 times a week and the weight is finally coming off.
I am down 14 pounds since early December!
I did not gain over Christmas, and I lost weight over New Years.
On Thursday I didn't want to go work out. I was tired and just wanted to go home. But then I thought about how happy I was at the doctors office the day before when they weighed me and the number was less than my previous weigh in.
A friend at work says I need rewards to keep going. When to get to "___" weight or size I will reward myself with "____". Well I don't have a system, I'm working out and eating healthy to get healthier, to be able to move better and do all the things I"ve missed out on because I've been heavy the majority of my life. I've never seriously dieted or done a workout program.
So I'll ask, should I have a reward in mind?