First off, you may be intaking more of something than you should, ie, sugar or fat even though you are possibly eating less. It is hard to say without knowing what you are eating exactly.
Secondly, with the weight training you are most assuredly building muscle and you may be trading muscle for fat with no change yet on the scales.
Thirdly, I don't know how long you have been at this, but losing weight takes time and every person is different!
Please hang in there. Continue on your exercise road, if you really want to know what you should be eating, go to www.dietician.com
and she has a calorie calculator. Answer the questions and it will tell you how much cal or fat to take in for a certain amount of loss per week.