Hi Skyeski
Your baby will be fine
The Prednisolone you are taking is only a moderate dose and only for a short time. Problems occure when taking this drug in the first trimester and for a longer period of time.
The main concern with the seretide is that there has been very little research on this drug and pregnant women. But as far as I am aware (I have just checked my books) there have no reported damage to the baby's of pregnant women taking this drug in the short term.
You need to also consider how bad your breathing is. And just by the dose of the Seretide I suspect yours is pretty bad.
If I can be of any further help I will be on line for a little while longer.