The important thing is not to get into a blame game. The really important thing is that they have done the right thing and told you.
Try to find out what they have tested positive and negative for. If they have one STI or STD there is a chance they have more than one, (as they have had unsafe sex to catch one infection), but they may not have been tested for the full range of STDs and STIs that Better2Know test for. In GUM clinics the standard tests are for: chlamydia, gonorrhoea, HIV and syphilis ONLY.
We suggest that you test for what ever your ex tested positive for, and whatever they did not test for. If you are not sure or do not want to ask then Better2Know recommends the Full STD screen which includes Chlamydia, gonorrhoea, HIV and syphilis and Hepatitis B, mycoplasma and ureaplasma.
Everyone’s circumstances are different, and it is your responsibility to choose the tests that are right for you depending on your sexual activity and what you know about your partner. If you are unsure then Better2Know recommends a Full STD screen. Once is enough to catch an STD, STI or HIV.