One of the tests they run on you early on is finding out your blood type. I am A- which means I am Rh negative. My husband is A+. So they gave me a Rhogam shot once during preganancy. After my son was born they checked his blood type and he is A+ too. So they gave me another Rhogam shot. During childbirth there is some blood that transfers from child to mother. If you are Rh- and your child is + you body can start building antibodies against the positive blood type. So if you get pregnant again and that baby has positive blood type your body fights it and you miscarry. The Rhogam prevents your body from making the antibodies. I have often wondered if that is why I have had 3 consectutive miscarriages since the birth of my son, but the blood tests do not show any antibodies in my system.
I hope this makes sense.

I'm in the same position as JessiCat. I'm 0- and my husband is AB+. I got a Rhogam shot at 28 weeks gestation and since my son is B+, I got another after he was born. When I wa pregnant with the third baby I miscarried, I had the antibody test done as well and it came back negative. I also got Rhogam after each miscarriage since 85% of people have an Rh factor, the liklihood of my babies being Rh+ is very high. Your blood type was probably checked while you were pregnant so you most likely don't have anyting to worry about. You could ask your OB if it's been checked to ease your mind.

I agree with the other replies. I am O- and was given a shot during my pregancy and after birth with my first child and during the preganancy with my second, but since he too is O- they did not give me a second shot. After I left the Dr. office after my m/c it dawned on my that I might need it so i called her, she said it was probably not needed since I was only 10 1/2wks but said it was better to give it anyway.
If you are Rh- and do not get the shot it does not mean you will miscarry but like JessiCat said your body will fight the pregnancy and you will have some complications. 38 yrs ago my aunt had her second child and my cousin needed a complete transfusion because of it.
If you call your doctors office the receptionist or a nurse should be able to look at your records and see if you are neg. or pos. It is a good thing to know.

Your dr. should have typed your blood when you had initial preg blood work done or when you m/c if you don't already know the type... if you are rh +, he/she probably just didn't mention it because it only matters if you are - (I am O negative so I got the shot) I have heard of people with RH negative blood NOT getting the shot if they were very early on because the risk of baby's blood crossing into mother's is so low, but I know my dr. gives the shot no matter what.

Thanks so much for your responses. I understand everything alot better now. It turns out that I'm not Rh negative so thats why it was never mentioned to me. Thanks again ladies (: