Lips purple

This morning when I woke up and started to do my makeup I noticed the top of my lip like the very top not the whole lip was purple like i got punched or something. It wasn’t hurting or anything but weird and concerned me does anyone have any ideas? Could pregnancy cause this? My room is very cold could it be that? They did disappear but im not sure when since I had pink lipgloss on and didn’t keep track but the purple is gone