You can have STDs and not know for years. You can have HIV, which has very few, if any, symptoms. You can have heptitits, herpes, or HPV and not show any symptoms for years too.
Try not to worry. Was that person you had unprotected sex with "high risk"? Did they have lots of partners before you? Did they use drugs?
You're doing a smart thing about getting tested. The best thing to do is educate yourself about STDs and their symptoms and incubation periods. And use protection from now on.