Need Help - 20mth old won’t sleep!

My 20mth old has just started over the last few days/nights not sleeping. Its like hes afraid of his bed. Won't sleep in our bed either, only way to eventually get him to sleep at night is to sit in a chair and let him fall asleep on me but he has to be exhausted for this to happen otherwise once down in his bed he starts to cry again. Totally refusing day time sleep - just continues to cry and cry every time I try the putting to bed - (like supernanny does). Am 8 1/2 mths pregnant and don't really need this right now and have been lucky enough that I haven't had any sleep issues till now.

REALLY REALLY FRUSTRATED AND NEED HELP!!

Or possibly teething? Would raising one end of his cot help?

Maybe hes unsettled with the preparations for the new baby going on? Sorry I dont really have a clue,...my 21 month old has never slept well! Hope it goes well at the drs. Isla always gets really strange just before her teeth come through, so could be that too.