I was eating healthy, and doing i was exercising(p90x) and i put on 2 pounds, why?

It could be what is called lean weight gain, maybe you need to look a little closer at our diet if you wish to lose weight, carbohydratess are our basic fuel, and proteins are the building blocks, if you have a diet that is too high in protein you may well gain muscle, so try a little less protein in the diet, and a few more carbs each individual is different, and so the balance will be different, it's a matter of trial and error, also as you need to watch the calories, the average adult male requires 2500 calories per day to maintain weight, but other factors need to be taken into account the main one is lifestyle, if you are very active, then you will burn more calories than someone who is very inactive, 1 pound of body fat= 3500 calories, so to lose 1 pound over a week you would need to reduce your calorie intake by 500 calories per day, (this is considered a healthy rate of weight loss), all this said you are eating well, and taking exercise, so it's just a matter of a little trial and error in balancing your diet, good luck.