Always use dental dams during oral sex. When starting a new relationship always use condoms. You should check that any new partner is not carrying an STD by having a check up. STD and HIV tests are available from local sexual health services. The most common bacterial STDs are chlamydia and gonorrhoea.
Women get pelvic inflammatory disease when chlamydia and gonorrhoea are left untreated.
You've got to make sure that you protect yourself by taking all sensible precautions, and insisting that a sexual partner do the same. Make A Noise.