I think if you were to study a vacutainer holder and understand how it works, you would easily understand why "not even a drop of blood can go up" into a person's bloodstream. The fact is that nobody in the world ever gets HIV from having blood drawn, unless the needle itself is re-used -- and that hasn't happened in the past 20-30 years, at least not in industrialized countries.
That will end this thread. I won't have any further comments or advice.
I still think a little about the episode and do have a problem understanding how not even a drop of blood can go up in my bloodstream. Especially if the tube got filled full. I heard that just a drop is enough to transmit.
Welcome to the forum.
I'm happy to confirm the accurate replies you had in the community forum. Vacutainer holders are designed to be re-used without risk of transmission of blood-borne infections. Most doctors, clinics, and labs would discard one that had visible blood, simply for esthetic reasons and to avoid alarming nervous patients like you. But there was no risk and you need not be worried. The senarios you describe would not allow contact of previous blood with your bloodstream, hence no risk. (Please also ignore any other "what if" scenarios that might come to mind. There none that are remotely realistic that would change my opinion or advice, so no point in asking.)
So don't worry further about it. Don't tested for anything, continue to nurse your baby, and don't hesitate to continue unprotected sex with your regular partner, if you have one. All is well.
Best wishes-- HHH, MD