Waking every hour and a half at night!

[Naspochi]

This sleep deprived mommy is starting to lose it. We've been doing BW and EASY for almost a month, LO is 14.5 weeks. Every since starting BW and the DF, LO has slept from 7/8 for at least 5 or 6 hours before waking up, the average is about 7 and a half hours including the DF.
This week he has started waking up every 1.5-2 hours, all night long! Since we started BW, he's never ever woken up before the DF, I know he shouldn't either b/c that's when babies have their deepest sleep of the night. I haven't changed his EASY at all and I'm even making sure he gets better naps in general (he's been hit by the 45 minute nap monster for 6 weeks now). But the last 3 nights he's woken up almost exactly 1.5 hours after I get him down to bed.

I know he's not hungry when he wakes 1.5 hours after a feed. We can always manage to settle him, it's easier with a feed but if at least 2.5 hours haven't passed since the last feed then I settle in a different way. He is EBF. I really really wish I could understand why all these NW all of a sudden and where the heck they came from?!

Here's today's EASY, LO has already woken up once 1.5 hours after I put him down at 8
E 730
A
S 915-1015 (nap extension didn't work very well)
E 1030
A
S 1145 - 1230, 1245-130 (nap extension success)
E 145
A
S 310-5 (nap extension super success!)
E 5
A bath
E 7
S 8 - 950, 20 minutes later he's still not back asleep!

Any ideas why suddenly all these NW? Is it the dreaded 4 month sleep regression I keep reading about? 4 nights ago LO slept 7 hours, ate, and then another 3, so I know he's got it in him...

Any help at all would be really appreciated! Thanks!

[becj86]

He's likely going to bed overtired - if he's only doing 1hr45 A times through the day, he cannot cope with 3hr from 5 til 8 without a nap and then be expected to sleep well at night. He probably should've been in bed asleep at 7 rather than 8. Make sense?

[Naspochi]

Yes, that makes perfect sense. And I've known that all along but the 3 hour last wake time has been in our schedule for at least a month and these are the first nights it's been a problem. I gave up trying to get a last catnap out of him because it was always a struggle and ds would never go down, just cry for up to 45 minutes.
I'll try for an earlier bedtime tonight and let you know how it goes! Thanks for the response!