Any relation between bedtime fears and what's happened during the day?

[lovesea]

For a while ds (aged 4) was really frightened at bedtime. I started staying with him until he fell asleep (no big deal as he's asleep within mintes) and he seemed to have settled down. Now tonight out of the blue, he's started again, crying, saying he's frightened etc. I wouldn't really have given it much thought but he's recently started at a new playgroup. Today when I picked him up, he had a huge bruise on his forehead. It was swollen up like an egg. None of the teachers mentioned it and when I asked about it they said that he'd said he'd done it this morning while I was still asleep (not true). The woman who runs the school had given me a hand getting the kids out of the car and confirmed that he didn't have that bruise when I'd dropped him off. I didn't really get to the bottom of it as my daughter was walking into the street and there were a lot of comings and goings. Though I intended to take it up with them anyway as several factors are cause for concern, now with the bedtime fears I'm wondering if something other than him just having an accident that nobody witnessed, has occured. Is there any relation between disturbing daytime events and bedtime fears?

[lyterae]

I haven't found any relation between the two, though in the past month DD has been experiencing bedtime fears for the first time. I think it's partially due to the age (4), maybe someone else will have more info on that.

ETA: I think that major life changes (new playgroup) could contribute to more anxiety in general. DD is getting ready to start preschool in the next couple of weeks.