Thank you so much for everyone's help, I've been implementing as much as I can but seem to be in sme crazy mess that I just can't get out of.
Wakeups are early and now he's crying and screaming from before 6am (although not every day). He's miserable most of the day and is having a nap from 1-2 capped. He goes and takes himself to bed for 'rests' or sleeps all day too. Gets his comforters, climbs in and I think he's happily playing but he tells me he's sleeping and to go away. Waking him takes me well over an hour to make him happy again. He's also super restless and crying and upset several times before midnight.
The other day we had a NND due to a family function and by 4.30 I was rocking and holding an uncontrollable 28mo who couldn't talk, walk, and actually went pale as his eyes hung out of his head. Wasn't a very fun afternoon but proof that he's desperate for more sleep. That night, after a 6.30pm BT he had a few crying NW as a result of OT and woke early - rolling around from about 5.30 then chatting from 6/6.30 miserable and throwing tantrums all day.
I've just found out I'm pregnant too (about 6 weeks) so I feel like I'm being run over by a train repeatedly and I'm desperate to help my little boy get the sleep he obviously needs. I thought of letting him have a bit longer in the day since it doesn't seem to have helped at all capping it. He still takes 30-40mins at night to quietly go to sleep (regardless of PD) and still wakes early. I'll to be mindful of BT but perhaps 7.30 (5hrs A) would be enough?