After 3months, my old jeans had just started to fit (tightly).
Another month went by, and they were actually a bit saggy on me!
So I guess 4months.
I did nothing to encourage weight loss, I think it was just the exclusive breastfeeding, sleep deprivation and pacing the halls every night...
I also eat quite healthily.
Don't stress, your body will be back in no time!!! I know, it's hard to imagine when you keep seeing a jelly belly and the tinyness of your old clothes, but it really will happen!