It could be either Earth, they might want to do a biopsy, which you probably won't get the answer to straight away. And also an ultrasound, which they might well be able to tell you there and then what they can see. But I would say to be prepared for a wait.
Its understandable you found it difficult to ring the BCN, its hard when you aren't sure what to say, but just to reassure you they are used to speaking to people who are upset, confused, worried etc. they will help you through any conversation.
Would your DH ring for you? he could explain the situation, and ask if they could give you a call, that way they'll be taking the initiative in the conversation, so it might be a bit easier. 
I banged the top of my head this morning, and the bruise has come out as black eye, - weird
- and obviously extremely attractive.