'Overweight'

I was apparently 4 stone overweight when I come off the pill and started TTC then I put on another half a stone. Still had no positive, I started slimming world end of may and my period at the beginning of June was 10 days late after I'd lost 8.5lbs, would this have been why I was late? Also, has anyone lost weight and been able to conceive much quicker? I'm hoping to lose 3st 10lb at least to get to my target. I have been TTC for a year now :(