I did zumba tonight while doing jump jacks i peed myself a little this has never happend b4 what can it mean?

Stress incontinence: You could have stress urinary incontinence which is urinary leakage caused by activity, cough, strain. Another type, termed urge incontinence, is due to unwanted bladder contraction. Stress incontinence is common in females especially after having previous vaginal delivery. If this was only occurance, would not worry but if it continues and is bothersome seek medical evaluation.

Incontinence: Loss of urine with activities like exercise can be caused by lack of support of the bladder and urethra. Some options for treatment include kegel exercises to strengthen pelvic muscles, use of a pessary (http://en.Wikipedia.Org/wiki/pessary), and surgery to resupport the fallen structures. Discuss with your gyn to determine which is right for you.