Why can i think of nothing but food?

mk345

So I feel like to answer this question properly you need a little background on my situation. It's been about 2 weeks since I changed my eating habits, I have a goal of about 25 lbs of weightloss, and so far I have lost about 5. I have gone on and off diets many times, and I'm hoping this is for good.... Every morning I have either a nonfat greek yogurt with fruit, one piece of whole wheat toast with egg whites, or a bowl of cereal (multigrain cheerios, special k...) for breakfast. Then I go to school. Some days I eat lunch at 11, some at 12:25. I usually eat something along the lines of 8ish babycarrots, an apple, and a PBJ on a orowheat 100 cal sandwich thin. Throughout the day, I am drinking lots of water. Then I get home, and usually have some fruit, veggies, or airpopped popcorn. Then I have dinner, I eat whatever my mom serves, which is usually something like lamb with peas, carrots, and mashed potatoes. Another example is a steak and pear salad- arugula, steak, balsamic dressing, and pear. I usually take a small amount of the more unhealthy things (mashed potatoes, fries...), or skip it all together. I only have 2nd helpings of vegetables or fruit. When we go out to dinner, I usually get either a grilled chicken sandwich or grilled fish sandwich and I skip the sides and just eat the meat or fish, without the bun.
Ok so now down to my problem-- All I can think about all day is food. Even if I feel normal, not even hungry, its the only thing on my mind. I think about my next meal, what I ate last time, constantly testing to see if my school skirt got any tighter after lunch. I'm always looking at what other people are eating, and thinking about it. I'm constantly googling things about health, exercise and nutrition. It's just all I notice, it's actually annoying.
Is this normal in the early stages of a diet or should I be concerned?