Breast clinic today - feeling anxious

I know it's ok for me to feel anxious but equally I feel guilty as everything may turn out to be fine! 
But I've got my breast clinic appointment later on this afternoon and I feel really anxious. Not sure how much concentrating I'll do at work today. 
Can anyone let me know what to expect? 
***update - all clear. Lots of cysts. Will be having regular mammograms from 40 and have been signed up to a family genetics programme. Really hope everyone else is doing ok xx