As relatively easy as it is for me to say, try not to worry too much.So my little girl is 2 weeks old now but had a shock yesterday as health visitor turned up to redo the heel prick test to retest for cystic fibrosis as my little girls result was inconclusive, they were very vague with any more information and just said it needed to be retested and will take 2 weeks for results so obviously worried now even though she said don't worry and it's probably just a contaminated card
Medical people are so used to carrying out these tests and then having to deliver that they develop a thicker skin. We're just not used to anything like that, so it hits us harder.
When I was pregnant with my daughter *cough*eleven*cough* years ago, I had to be tested and monitored for spina bifida (and I had more pictures of her before she was born than I did for a while after!) and they were quite blase about it; it's just how they deal with it.