I am now just over a month post partum, I had a c section and my incision still hasn't healed all…

I am now just over a month post partum, I had a c section and my incision still hasn't healed all the way. I am still having a little drainage and it is about 1 in long. I know he left a little open for it to drain, but is it supposed to take this long!? I have been back 3 times cause I am worried and they say it looks fine. Anyone else take this long to heal???