Hi LittleHorse, I read some of the previous post here, Oscar sometime give a false result. If you are really worried maybe can consider MT21?
Im also pass 35yrs and expecting my No 1 as well. Instead of Oscar, I went for MaterniT21 which is a non invasive blood test.
This test is able to test you whether the baby has any Downs
More info can be found here MaterniT21
MT21 test (I think is 99% accuracy) and will give you the gender of the baby in the result as well.