An error occurred during the last blood test, which was last week today. I know there are a few blood tests needed whilst pregnant, but how many? And since there was an "apparent" error in the last test, is it safe to just let them take more? I'm 29 weeks in now, and I'm worried that I won't have enough blood for the baby. Two blood samples were taken from me last week, I don't understand how BOTH of them could have an error. What should I do?