There may be several possible reasons for not losing weight, you just need to figure out which one is most likely in your case and make an appropriate adjustment.
If you create a calorie deficit, then you WILL lose weight. There is a lot of misinformation about this idea that if you don't eat your calorie budget, you'll starve and the body will hang onto calories and prevent weight loss. Make sure you are capturing your actual calories. Focus on tightening up tracking. Measure/weigh all foods/drinks you consume. Log basic foods.
Calorie counting and our nutrition tracking service are time-tested and proven!
Please see Weight Plateau article from our Diet Library for detailed discussion and more information.
Few More Ideas
1. Water weight is suspected if you gained while eating a reduced-calorie diet. Weighing oneself first thing in the morning is a good idea to avoid variation due to hydration/time of day.
2. Track sodium - higher sodium the night before often means water retention and a higher water weight the next morning.
3. Track accurately. There might be an error while logging foods or/and exercises.
4. Understand your caloric goals. Learn about helpful tips if you are a new member.
5. Double-check again that you are logging foods and recipes accurately.
6. Send a question in the "Ask RD" Community forum.