I am 6 months post partum and still experience some leakage when I sneeze too hard. It's getting better but I hope it improves. I try to do my Kegels everyday. Most importantly I wear a pantyliner to help absorb if it happens.
Do your Kegels! The vaginal muscles will loosen after childbirth, but it's not to the extent that you'll become incontinent. The likelihood does increase with subsequent pregnancies!
thanks