Is anyone else a negative blood type while pregnant?

Britney • I'm a happily married to the love of my life and I'm a 27 year old who is graduating university soon this year and is hoping to start having some beautiful babies soon! We have had one pregnancy and miscarriage at 7 weeks so far hoping for a rainbow baby
I went to the Er yesterday and found out that is why I have been spotting so much because me and the baby have opposite blood types which is crazy to me! The doctor said in your first pregnancy it won't hurt the baby at all does anyone have any experience with this? Did it affect your hcg levels at all?