Still working out

Well I'm still working out, weights 3 days a week, bike 5 or 6 days a week. I'm up to 12 pounds on my weights and 8 miles on my bike but I'm still not losing any weight and I don't understand it because I seriously don't eat that much. Here's a typical day:

• Breakfast: 2 pieces of toast (low cal bread), grapes, 8 oz milk
• Lunch: salad or fruit, 4 oz of light yogurt
• Afternoon snack: whole wheat crackers or slimfast bar
• Supper:Pork chop, rice, mixed veggies, salad
• Snack: small bowl of cereal

I'm trying to work my way up to 10 miles a day on my bike by adding a half mile a week and I'm thinking maybe add another weight lifting session once or twice a week. The doctor wants me to lose 10 pounds by the next time I see him but I dont' see it happening. I only have about 5 more weeks.