I don't know if this is a sleep regression or something else. I don't even know how to ask. My baby had his 6 month well baby visit and he is fine and in good health so...

Why when we put him to bed does he wake screaming every few minutes? He calms immediately when we go in (either myself or my husband) and falls asleep. Then he somehow wakes again a few minutes later! I thought sleep cycles were supposed to be 50 minutes to 2 hours depending on development.
Same thing waking screaming every few minutes for a few hours and then he's out for the night (with the regular 3-4 wakeups, 3 feedings).

What is going on? Has this happened to you/your LO?