I went back later today to read some of your posts, your situations sounds so much like my own. Spot of incision just doesn't heal shut, continues to get bigger and deeper.
First, be assertive at this point, you have something wrong and you need to get it cleared up. You may need a wound care doctor and they are wonderful at what they do and their knowledge. I think I wore my wound vac about a month maybe a little longer but had to give it up a bit early as I developed irritated skin, that felt like a rug burn to my good skin that was covered, but don't fear even when this happened those doc's had things up their sleeve to keep my knee healing and moving forward. The wound vac I got was a rental unit the dr. set me up with.
I was concerned when I found out I had infection that I may have ruined my need knee replacement, but thank god I had a slight infection. I had no drainage to mine, no redness, swelling, or heat given off that area and still had infection. In fact the Dr's that looked at it prior to the wound care Dr, said yes it's not healing but it's not infected. One thing about the wound care Dr, they believe at starting at square one, and that is checking for any underlying infections, or if you are a diabetic.
Also, all PT had to be stopped as they didn't want any additional pressure and stress put on the wound. Even after mine healed I was asked to not go back to PT or stretching on it till the wound skin had thickened.
We're all very concerned, I know I am. Keep us all up to date on your current situation.
Actually another thing with the wound Dr, was I could shower but I had to cover my dressing with press and seal wrap which actually works and holds better than Saran wrap when showering, they didn't want any bath water getting into the wound. All dressing changes were done in a sterile environment. I went to our local hospital twice a week for packing of the wound and they measure it each time, and for the dressings to be applied (so I know you spoke about bathing and letting the water run over the area. I did prior or in the early days also, but after seeing wound care Dr, that had to stop.)