Is this gum lump over implant normal? Dentist said it was normal tissue healing. (photos)

I had extraction and immediate implant in bottom right molar 5 weeks ago. 2 days later got severe constant throbbing in socket. Finally subsided after 3 weeks and 3 courses of antibiotics. Dentist baffled as to cause as everything looked good on exam, xray and CT. Things seemed ok for a week then 4 days ago I developed a lump on gum over the implant. Saw dentist 2 days ago and he said it was normal tissue healing. Due for crown fitting in 1 month. Does this look normal? It's mildly tender only.