No, it doesn't mean you are infected. It means you did have a risk. You DO need to test. But remember, the odds are low from a one time encounter and you have no idea if the woman had HIV. She probably didn't. Really. Take a 4th generation Duo test at 28 days and it will probably be negative. Buy some condoms, have safe sex.
A duo test is conclusive after 28 days and any other test after 3 months.