(cant delete my last comment) if you are rhesus negative, and your husband is positive it will not cause harm to this pregnancy, you will be tested and you'll get an injection so future pregnancies will be fine too x
unless someone is rhesus O negative and the other is rhesus positive, it will only be a problem later in pregnancy. Around the 28th week (do not quote me) you will recieve an injection to avoid problems in your second pregnancy. It would not be a problem conceiving and both you and your husband will be tested to see what group you are in.
Have a chat with your doctor, it should be fine to conceive. Any problems that may arise will be dealth with accordingly x