What happens when spacers are left in too long?

My dentist is really bad at his job and I was suppose to only have them in for 4 weeks but he reschedualed and won’t be able to take them out until week 6 (second time this happened) are there any issues that can arise from this? (The top right one is bothering me, I can feel pressure and it’s place But I don’t feel anything for the other ones)