If you've gotten rid of some body fat, you may now have less estrogen and more testosterone in your system. That would make things more pronounced down there. Natural body fat produces estrogen in both men and women.

It's also possible that increased blood flow is happening. When people are out of shape they can get some blockages to the blood flow anywhere in the body, including in the groin area.

Congratulations on getting in shape. It's not easy but well worth it for many reasons!