I agree with Alaysha. They will never completely go away, but there are things you cna do to help minimize them. If your still in the middle of your pregnancy there's no point in stressing over them now, trust me after you give birth ones that you didn't even know you had are going to pop up.
keep on using bio oil because that is what am using after birth of my baby and it reduce its appearance
There is nothing you can do. After you give birth they will slowly fade and turn grayish and then bio oil and the like can help make them less noticeable but they will always still be there. Tanning (once you are not pregnant) can help them disappear as well.