Negative RH factor

I was totally freaked out yesterday, but today my mind has been put at ease. When I found out my blood type is A negative and that I needed this RhoGAM shot I started researching because I am a librarian and that is what I do. From all I read it said I needed that shot within 24-72 hours of the D&C procedure so that in case my blood mixed with the baby's blood I would not develope and RH sensitivity. I convinced myself that I was screwed--I had the antibodies and future pregnancies would be a great danger for the baby. Well, my doctor finally called me back this morning. He told me that a fetus at 7 weeks does not have red blood cells yet, so the risk of me developing the sensitivity is not there, but I need the shot at a precuation for a future pregnancy as if I gave birth. Any woman with RH negative blood, gets this shot around 28 weeks and again after giving birth for a future pregnancy. So I am OK and a future baby will be OK too. If Justin also has negative blood it is a non-issue because the baby would also be negative. There is way too much the know in this world.