9 month sleep help!

So my little boy is a week away from turning 9 months. His sleeping at night had started to get really good, he’d go down at 7pm, I’d dream feed him at 10pm then he’d sleep until between 7-8am. This past week that all seems to have fallen apart! He will sleep like usual until about 1-2am, then it’s a nightmare! He’s away every 1/2-1hr. I’ve wasted so much formula through the nights making it up to see if thats what he wants, I give him calpol if I think he needs it, change his bum, tried everything! But he literally doesn’t want anything. He’s just awake and crying for no obvious reason. I wondered if it was teething, but he’s had 2 come through previously and I don’t remember him being this bad at night!!

I’m so exhausted, being nearly 12 weeks pregnant also, its really taking its toll! Anyone experienced anything similar?