Depending on what type of tummy tuck you had the swelling will resolve in a few weeks. If you had a lipoabdominoplasty which is the more recently desribed orocedure ,the swelling resolves quicker. If you had a traditional procedure it can last quite a but longer and even up to a few months. In addition , the older traditional procedure is more prone to fluid collection under the flap (seroma)which can last for several weeks. Either way it will resolve in time and the odds of there being something to worry about is low.