Should I  talk on the phone while giving blood?
Is there something that you need to talk about?
Yes, I'm thinking of my ex-girlfriend and what we used to do together.
Can this wait for later? I think that you should pay closer attention to the person taking your blood, they might need to give you instructions and stuff.
I'm worried that I won't be filled up enough and will learn I have Hemophobia.
That is understandable, I think you should voice you concerns to them. The medical professional will be able to walk you through the procedure and make it easier for you, but you shouldn't talk on the phone.