I am never sure how many calories I am really burning when I do exercise. Quite often you will have a great workout and according to the numbers you only burned a couple of hundred calories. There is a lot more to calorie burning than what the numbers may say. Some question you should ask yourself are:
How long did you exercise?
How hard was the workout to you?
Did you gain any muscle in the workout?
How long where you tired for after your workout?
You have to remember when you workout that the exercise you did this morning will temporarily raise your metabolism for 12 hours after that workout. Also there is some muscle gain if you didweights or pushed yourself hard.
If you would like to see how much calorie buring you did during your actual workout you can consult a page that I found for this. Just remember to take these numbers with a grain of salt in the larger picture.