There must be something they can give you that is less threatening to your baby. I don't know the impact oxy has on fetal development. Have you googled it to get info?
I mean, there are pregnant women who are in auto accidents or who need surgery during pregnancy.....they have to have some type of pain killer.
Talk to your doctor.
I had to be on Codeine sporadically throughout pregnancy for migraines...doc said it was ok if I didn't abuse it...maybe you could ask about that?