The only sure way to know your status is to get an HIV test. You can buy an HIV home test kit at a pharmacy, go see your regular medical provider, or drop into a local HIV testing site: https://gettested.cdc.gov/
HIV antibody tests take 3-6 weeks to turn positive after someone gets infected with HIV. If the sex without a condom was less than 3-6 weeks ago, you can talk to your provider about getting an HIV RNA test instead of an HIV antibody test. The HIV RNA test becomes positive 10-14 days after someone gets infected with HIV.