My weight affected my PCO. And it was when I finally got UP to my recommended weight, that my cycle stopped! But since you show no signs of polycycstic ovaries, not sure on how weight affects fertility. I do know that with more fat, the body produces more male hormones (gosh - i cant remember the different hormones now!) and it basically screws with the delicate balance of hormones which cause ovulation. My OB said that my weight gain, while well within my healthy weight range, is what triggered that imbalance, and I lost my cycle. Metformin did the trick for me tho

I hope you get some answers soon.