Why so early???!!!!!!

For the past 2 or 3 weeks my kids (ages 3.5 years and 2.5 years) have been waking up at 5 am sometimes 4 am. When they wake up they come into my room and I put them back to bed but they won’t go back to sleep and continue to come into my room.

I’ve tried taking my oldest’s nap away, all day play (stoping for nap, lunch, snacks etc), later bedtime, later nap, extra snack just before bed, nothing has worked. Their pediatrician suggested melatonin and Benadryl (not at the same time obviously) and those just make going to sleep smoother but not helping the length of sleep.

I’m currently 36 weeks and I’m desperately wanting to sleep past 5am. Hell even if they woke up at 6 or 6:30 that would be fine!!!

Can anyone relate??