I've had the shot with all my pregnancies. They will give it anytime you experience bleeding during pregnancy, around 28 weeks and then after delivery if your baby is rh positive.
I had with all of my pregnancies. You are rh negative if the baby is rh positive you will get another one after delivery. When you are negative and the baby is positive the blood factors compete and can cause problems the Rogram keeps that from happening. If the baby is negative there won't be any problem and you won't need another. Ok that's kind of simplifying it but that pretty much the gist of it.