Having a hard time losing weight help!!!!!!!?

HI just had a baby over 2 months ago and I have been going to the gym at least 5 times a week and have been working out really hard. I also have been watching what I eat and the scale is not moving. My body does look like its tightening up but I don't understand why the scale is being so stubborn. Last year I lost 40 pounds before I found out I was pregnant. I 'm doing the same workout and eating regiment that I did last year but nothing. I'm actually considering a diet pill to take in conjunction with the diet and exercise but I'm scared. Do any of you have any tips on what I can do to get this weight off of me. I'm used to being able to lose 2-3 lbs a week. I'm not even losing 1 pound a week nothing at all please help me. Personal experiences anything you know will be a big help.