I am A- and DH is A+. They tested bubs from his cord sample when he was born and held off giving me the Anti-D until the results came back. He was A- too so I didn't need the shot.

If you are -ve it means you have 2 -ve genes, as in -- if you are positive, you could either have two positives ++ or a positive and a negative +-. Therefore if you and your partner are both -ve you can only have -ve babies (-- plus --). It is harder if you are +ve cos then you wont know what your baby might be. (cheeky side note - if you are both negative and you have a positive baby...you have some explaining to do!).

I find it really facinating. We both found out our blood type when we gave blood. O- is the universal donor - they can give blood to ANYONE so very handy to have one in the family