I have great news for you! Your question doesn’t change anything except to make the answer even more promising. ☺️

From your description the nurse used a Betadine swab. It’s a povidone-iodine that’s highly effective against bacteria and viruses. It’s applied to skin before surgical procedures! I’ve had it used on me many times before having Picc lines, ports installed and bone marrow biopsies. And since the needle was sterile and the nurse didn’t touch the needle there would be no way of any cross contamination for you during your donation.

I’ve posted an article from Pub/Med titled, Inactivation of human viruses with Povidone-Iodinewhich, tells how effective it is against viruses, including human immunodeficiency viruses and Covid.
https://pubmed.ncbi.nlm.nih.gov/9403252/
Does this help make you a little more confident that you have nothing to worry about? You should be able let this worry go.