Obviously, you had manifestations of what appears to be a superficial surgical site infection (SSI).Antibiotic therapy had been given and it appears to have stopped draining.As you don't mention any local swelling or tenderness, it has probably been controlled.
The abdominal distension could be caused by a number of factors (antibiotic therapy included).
Hopefully, your symptoms would settle down soon with symptomatic management as advised by your doctor.
Deeper surgical site infections(including organ/space SSI's) appear to be less likely at this stage in your case as you don't seem to have any other symptom(apart from abdominal distension).
If the symptoms should continue or worsen, of course one should exclude deep SSI's.
However, your doctor is in the best position to examine you and decide if further investigations are warrented at this stage or not.
MB BS, MS, FRCS(Edinburgh)