Weight Gain on NuvaRing

I've been on NuvaRing for 3 months. Overall this has been the best birth control option with no mood swings or fatigue. Now going on my 4th month I am noticing some slight weight gain not so much on the scale but most notably in my stomach and thigh area. I have what you would describe as a "noodle" or "boy shape" body type so I find it interesting that my shape is becoming more womanly with added hips and curves that I never had before. Has anyone else experienced this? I am speculating that it is the bc hormones and wanted to know if others have had similar experiences. For instance when you noticed additional weight did it seem harder to lose it being on the pill vs not, certain areas of the body change etc. Thanks!