Why not start off the year with a clean slate? If you are not in a long-term and monogamous relationship, it's a great idea to get tested for STIs so you can have peace of mind when it comes to your sexual health. Your gynecologist can test you for all STIs including HIV, gonorrhea, and chlamydia. They can also check for HPV (the virus that causes genital warts) by doing either a HPV test or a Pap smear. They may even recommend that you get the vaccine Gardasil that can prevent certain types of genital warts (the types that cause cervical cancer).
I know it's not exactly the most fun way to ring in the New Year, but the feeling of relief will make it all worthwhile.