DS is nearly 10 months old. His bottom 2 teeth came through together at about 6 months old. His top 2 have been very slowly coming ever since. The last few days they’ve been really swollen and sore-looking, and DS has been upset, so I knew they’d be breaking through any day now. However only the left tooth has actually broken slightly through the gum now, rather than both at the same time. Is this OK? Will the other one catch up?