I'm glad you asked because there are a lot of misconceptions out there about transmission. It sounds like you are concerned about another person's semen coming in contact with a possible cut. We are not medical professionals so couldn't determine your level or risk just based on the description, but we can provide information.
Do you know if the person you had this encounter with has a positive status? And if so, if they are being treated they may have an 'undetectable' viral load which eliminates the risk of sexual transmission, so you'd have to know if their viral load is undetectable.
In terms of transmission, we do know that HIV is not expected to live for long outside the body so this may lower your risk. More information on transmission here: https://h-i-v.net/transmission.
We think of testing as just a part of routine health care, so if you are looking for a place to be tested (or to get PEP, which is the medication you can take after a possible exposure) you can find one here: https://h-i-v.net/living/testing-locator
I hope this provides you the information you need. Please keep us posted on what happens next, and if you get a test and have more questions let us know! - Liz (Team Member)