Congratulations on your weight loss, very impressive! The measurement method of calculating body fat is notoriously inaccurate and measuring with calipers should be done by an exercise physiologist using a variety of different skin-fold locations. If you cannot see your abs I doubt very much that you are under 18% bodyfat. The hormonal imbalances could be contributing to your fat deposits and will probably disappear overtime. Make sure you are doing HIIT and HIIRT type of training to boost HGH and Testosterone.