Lately I've been waking up around 4 am or so and then (sometimes) falling back asleep. Maybe I am having a sleep regression?
I usually find myself waking up between 1 and 4 am. I'll be up for 1-2 hours, then fall back asleep. I've never slept like this before, but apparently it used to be really common?
http://m.bbc.co.uk/news/magazine-16964783
Do you usually sleep in one stretch, or do you wake up in the middle of the night and then go back to sleep?