Welcome back to the forum. Thank you for your continuing confidence in our services.
You needn't be worried at all. Your doctor was right: this definitely was a no risk event.
Your doctor is also correct that HIV cannot survive any length of time in the air. You either found overt misinformation or misunderstood something you read on line. But whether HIV can survive really isn't the point and not important. We know such infections never occur: therefore the biological reasons don't matter much. In the earliest days of the known worldwide HIV/AIDS epidemic -- in the mid-1980s, before HIV was even discovered as the cause -- public health officials were able to inform the public that there is no risk from non-intimate personal contact. How did they know? For the same reasons we have relearned time and again over the years: there are no HIV infected patients without the traditional risks of unprotected sex or obvious blood exposure. If you think it through, you will understand that we all have non-intimate interactions with HIV infected people all the time: they cook our food and serve us in restaurants, cut our hair, give us manicures, operate on us (yes, there are many HIV infected surgeons), exchange money with us at cash registers, and otherwise participate with us in daily life. And obviously some of those thousands of interactions (including your own, beyond this particular pharmacy customer you know about) had to involve the sort of blood contact that you are worried about. If these events carried risk for HIV, there would be at least a few HIV/AIDS patients who had not had sexual or drug related blood exposure risks. But there are none. Even in the busiest HIV/AIDS clinics, everyone has the standard risks: when someone initially denies them, it turns out they were being untruthful or were otherwise mistaken, e.g. did not know a sex partner was infected or at risk. Even the household contacts of HIV infected persons never get it, even after 20+ years sharing kitchens, bathrooms, toilets, eating utensils, etc (assuming they are not also sex or needle-sharing partners with the infected person).
So no risk and you should not be at all worried. You should not be tested and should continue your normal sexual relationship and practices with your boyfriend.
My final advice is to stop searching the web about all this. Anxious persons, whether about HIV of life's many other risks, tend to be drawn to information that reinforces their fears and to miss or ignore the reassuring information that also is there. Nate Silver, the now famous statistician of fivethirtyeight.com, wrote a book about statistics, "The Signal and the Noise". It it he writes "Give an anxious person a computer with an internet connection in a dark room, and soon he'll be mistaking his cold for the bubonic plague." Don't make that mistake!
I hope this information is helpful. Let me know if anything isn't clear.