Can a umbilical hernia appear after gallbladder surgery ?

i had a laparoscopic surgery to have my gallbladder and gallstone taken out. this happened november 17, 2010. a few months ago i noticed a sort of ball form where i had once had scars. is it normal to develop a umbilical hernia after a gallbladder surgery ? btw a few months my dumb self carried a 5 gallon crystal water bottle.