I don't think blood types matter for breastfeeding. You should be fine no matter what type you have. The only time blood types matter that I'm aware of is if you have a negative type blood during your pregnancy because then you'll possibly need an Rh shot.. I think. I have a positive blood type so I'm not 100% sure about all that, but as far as breastfeeding goes I don't think it matters and you should be fine.