Last week I had sex without using a condom. Should I be tested for STD’s?

You can get a STD by having unsafe sex, even if you take a risk just once. The hard part is that people often don’t have symptoms. Therefore they don’t know if they got infected or not. You only know if you do if you go for a physical check-up. But when do you decide to have this done? Some people are infected after fucking one time without a condom, while others take risks all the time and don’t get infected. So there is no general answer to your question. But if you have taken a risk, it’s wise to go for a STD assessment and not take any more risks in the future. Use condoms whenever you have sex. Then you will never have to face this problem again.