If you have made a change in your dietary habits, e.g you are eating less carbohydrates and more protein, you may lose fat and gain muscle mass and that explains why you don't loose much weight but you fit in your old jeans. Unfortunately, BMI is used by the medical community to define obesity. This index is not as effective anymore but it is still the rule. If you want to know if you are going the right way, take a measure of your abdomen circumference, as well as your hip, high par of your tights and arms. You will notice a reduction on your measurements as you are losing fat and gaining muscle, which also will help you burn more fat.

Awesome If you're not loosing weight you're loosing fat your body works inside out

You're probably recomping. Obesity is a BMI above 30 and also there is a thing called "normal" weight obese. Skinnyfat people generally are underweight or "normal" weight but usually high body fat percentage. Some are shockingly higher than me. (I'm about 31-33% some of them have 40-50%+ body fat) I have a BMI of 30 and I wear misses medium, mens medium, and boys 18 husky in tops. Bottoms I wear a 14 and 15. So obesity isn't really defined by sizes. I don't focus much on the scale I'm more worried about body recomposition.

Awesome
That is why I stopped weighing myself and just go by how my clothes fit