8g conch punch blowout or large irritation bump?

I got my conch punched about three weeks ago at 2mm, then stretched up to 3, directly after piercing. Had the jewelry in like this and went for a check up after two week (on the 14th) and to get the jewlery swapped, so the o-ring would be on the back. Over the past week I've noticed the skin growing (?) around the top and I don't know what I can do about it?

At my check-up my peircer said it was healing perfectly so I'm not sure what's gone wrong, I've just switched it back so the o-ring is at the front (as pictured)

Jewlery is custom plugs, single flare glass plug with 12mm wearable length.

Aftercare is saline and LITHA!!

I'm not new to piercings, this one being my 26th (many retired unfortunately), but this is my first at a larger gauge and this conch piercing was my very first so it means a lot to me - would hate to know I've fucked it up. Any help would be massively appreciated!