A sexually transmitted infection (STI) is an infection that spreads through sexual contact (where the genitals touch) so you don’t have to only have sex to get one.
Some people don’t show symptoms so you or your partner could have one without knowing. If you have any doubts, get tested for STIs. You can get tested free of charge at any government clinic and your test results are confidential.
And use either female or male condoms! They protect against most STIs.