STOP reading the guidelines on the FDA website. Those aren't intended for you to interpret. They're intended for health care professionals. If you don't know what you're reading, you will interpret it incorrectly, as you have done. If living on a farm made the tests inaccurate, there would be warnings ALL over the tests.
You don't have HIV. Stop fixating on HIV and move on with your life.
The only risks for HIV in adults are:
1) Having unprotected anal or vaginal sex, or
2) sharing intravenous needles with IV drug users.
You cannot get HIV from an object, EVEN IF the object has blood or other bodily fluid on it. HIV loses its ability to infect once it is outside of the body.
If in doubt, re-read items 1 and 2 listed above.
You had ZERO RISK for HIV. There is no information you could add to this event that would make it a risk for HIV.