Quick question about teething. One of my sons bottom molars is coming through and there's like a tiny red/purple line on the top, not sides. It almost looks like a bruise or that it was bleeding or something but no blood comes off on a cloth when I try to see if it is bleeding. He has 2 top molars that have already came through but I had no idea they were even coming in so I'm not sure what they looked like prior to breaking through the gums. It was super swollen last week and it looks like the swelling went down but now there the line. Is this normal for the molars or what?