If you have had several sores on several occasions, it may be herpes or possibly HPV (Human Papilloma Virus--genital warts). Are the sores very painful??? Typically with syphilis you would have a not so painful chancre or sore, that would heal up in a week or two. The disease would progress relatively symptom-free...possibly for years until more sores began to appear. Whatever the case, you need to get medical attention and stop having all sexual contact right away!!! If it's syphilis, you can be put on antibiotic treatments and most likely be cured of it. Best Wishes!