Hi Hope in Healing.
I'm not going to be a whole heap of help aside to say I would definitely get this checked out. Thankfully after ten years of fistula woes mine has healed but I had a draining seton for the majority of those years (in the same area), and anything out of the ordinary I would always get checked. While good not to have heat or redness, to have slight pain and swelling in that area is enough reason in my book to get it looked it.
Try not to worry too much, easier said that done I know. Let me know how you go.
Big hugs
Debbie