My stoma's getting fat!

I've had this stoma for over 6 years and it's always been fairly long and skinny. But it's gotten shorter and fatter. Not short like sunk back into me, just somewhat shorter. I noticed last week when I changed that it was kind of pink at the end and sort of mushroomed around the opening. that was a new thing. I don't have any pain and as soon as I took the wafer off it was back to normal. But I've been using the same size for years. So tonight when i changed it was the same color all over but still mushroomed a little at the top. Again as soon as I took the wafer off it was fine. I made the hole a little bigger. But I noticed it was a little shorter than usual too. Last week it wasn't. I know they also change size depending on what they are doing. But is this something to be worried about?

Yeah it works just fine. No pain or anything. It just seemed weird to me.