Saline return

I really hope maybe someone can put my mind to ease a little, and I’m feeling a bit embarrassed to ask.. But when I was donating and it was time for the saline return, towards the end I kept seeing little debris coming through the tube. It looked like little bits of clotted blood. I asked the tech and she said, yes, that’s what it was and that it was normal. She then showed me where they have a little placebo the machine that catches them. However, I definitely saw bits that when all the way through the tube up to the needle in my arm. Should I feel concerned? Or am I just being a bit paranoid?