I had unprotected vaginal sex about 14 weeks ago. There was also unprotected oral sex and deep kissing. At the 8 week mark, I got tested for all STDs including syphilis. Everything came back negative. After 12 weeks had passed since my sexual encounter, I noticed a painless sore under my tongue on the floor of my mouth. At that time it was small and I started rinsing my mouth with warm water and salt, thinking it was just a canker sore. 2 days passed and the sore got larger and smaller tiny sores started appearing near the larger sore. Another day passed and white papules appeared inside my cheek touching the top row of my teeth in the back. The tip of my tongue also felt burnt, even though I hadn't drank or ate anything hot enough to burn it. I stopped using the salt water and the burnt tongue feeling went away after 4 days and the sores and papules have gotten smaller, but are still present. Is there any way this could be syphilis or any other kind of STD? Should I get retested for syphilis?