My gums are swollen and I'm soon done with treatment is this normal?

I am on trays 17/20. I put trays 17 in a week ago and my gums in between my teeth are still swollen. The teeth where my buttons are hurt really bad when I take my trays out. I feel like I'm going to rip my teeth out. It just concerns me because I've only had this pain when I got my buttons on back when I got trays 3. And that only lasted about four days. Why is this happening when I'm almost done with treatment? Is it normal?