TTC with O- blood type

Lisabet
I'm not currently TTC but we will be once we get married on June, 11th, 2016 :)
I have O- blood type and I've heard a LOT about there being problems with TTC and having this blood type. I'm really worried. We both want more kids (his kids but I raised them), and I'm worried that if and when I finally get pregnant that there will be lots of problems.
What have you heard about this if anything at all? 
If you have O- blood type what did you do, and did you have any problems? 
THANK YOU!