How much weight can I lose in a month with this diet?

Okay, so I don't have a scale, but I'm pretty sure I weigh in around 130 - 135 lbs and I'm 5ft 5in tall. Early last spring I had my weight down to around 117 lbs and I was happy at that weight. Then I had a dystonic reaction to medication and I could barely walk, let alone keep up with my 2 miles a day on the treadmill, so I gave up, starting eating bad and spent most my time sitting around, rarely getting exercise. I'm pretty much recovered now and I put on quite a bit of weight I want to lose. So, I started dieting three days ago and this is my plan - For fluids, I drink mostly water or hot teas after meals (green tea during the day and chamomile at night). For breakfast - One cup of cereal (raisin bran crunch) with skim milk or a gl of kiefer or an acai drink. For lunch and dinner - Usually salads with a small amount of feta cheese, some sort of meat and other veggies or homemade soups with potato and veggies. For exercise - Either the treadmill or eliptical machine three times a week, set at 4.5 -5 (is that mph??) for 2 miles (about 20 minutes). Daily stretching, sit-ups, push-ups. When I can't get to the weight room, I go for runs around the neighborhood. I'll do short spurts of running, then walk, then run again and so on for about 40 min. I try to get vigorous exercise at least three times a week and the other days at least some sort of exercise (walking, pilates, etc.) So, my question is, how much can I lose in a month if I keep this up? I'm hoping to lose at least three pounds a week.. Oh, and I plan to take one day a month were I "reward" myself and go to a nice restauraunt, have a few margaritas, etc. Oh and I'm 22 if that helps.