When we left DD's daddy late last year, her sleeping routine went all haywire.

Someone suggested that i keep her up late e.g 8.30pm and so i tried that.
It really helped us get thru that difficult time.

Now she's gone back to an earlier bedtime, so it hasn't made things worse (for us).

Do what works for your child, like MummeNurse said. Some things work, that normally you wouldn't do, but there are always special circumstances (you being pregnant). If it saves tantrums and means you all get a better night's sleep - sounds good to me.