(((hugs))) Cyndie - it must be so hard trying to fit his naps round school runs.
Maybe the later BT last night was a tad too much for him? Or maybe a 3h 15 A time too much after a 30min nap

(having said that we did 30min AM nap followed by 3hr A time today & DS napped for 40mins

).
I would be wary of letting that AM nap creep its way earlier again though, or you might find your WU starting to get even earlier. I am convinced this is what helped us with our EW & you with yours. You might just have to ride things out for a while if he is extra sleepy with teething though.
If its any consolation our naps are in a mess too. DS is poorly with cold & chesty cough & he is seeming rather tired in the AM & is dead to the world when I go to wake him but then he is resisting his PM naps. I feel like I havent worked out the right A times for him.
Yesterday went:
Wake: 6.15 (11h 15 night sleep)
Nap: 9.45 - 10:30 (let him have 45mins since extra sleepy & poorly - he was really crabby when I woke him)
Nap: 2.30 - 4.00 (I put down at 3.5hrs A time but he did 4hrs - after a 45min nap

) woke at 40mins crying then back to sleep. Woke himself at 1.5hrs)
BT: 7.30 (PD at 7pm but chattered for ages - my guess is UT due to PM nap being too late in day)
Today:
Wake: 6.25 (11h night sleep)
Nap: 10.00 - 10.30 (took 20mins to settle. I woke him - he was reasonably happy)
Nap: 1.30 - 2.10 (I aimed for 3hrs A after a 30min nap but TBH think he was UT. Bouncing in bed, chatting, then woke himself, happy after 40mins)
BT: 6.50 (think should have done earlier BT but O rarely tacks on lost sleep at night so will usually just mean earlier WU)
BT: 7.30
I'm finding he needs to go back to a 2 nap day after a few 1 nap days, but any more than 1 & it all goes wrong again. I'm not sure if I just need to allow a longer A to his PM nap, but then that will leave us with not enough A to BT. I don't really want to lengthen his day if I can avoid it as he then sleeps a shorter night. So my only options are to assume today was down to his cold & try again tomorrow but maybe do PM nap 15mins later, OR cap the AM nap even shorter, OR do 1 nap. And Stick To It so he gets used to it. What do you think ladies
