The star has tweeted a series of cute pictures of her expanding tummy filling out her sparkly green stage costume.
Later, the mum-to-be tweeted another picture showing her in her wedding outfit for the Shrek finale, joking that she was having a 'shotgun wedding.'
Announcing her pregnancy last month, Amanda said she would be leaving the show early to look after herself and her baby, following her stillbirth earlier in the year:
'Due to its physical content this means I will end my contract with Shrek The Musical eight weeks early. I will endeavour to continue the show until the 3rd October. I do however ask you to bear with me as I will be putting myself and this pregnancy first.'