Sometimes it can take as long as 3 months for the syphilis blood test to become positive; but more than 90% will be positive within 6 weeks. Almost certainly you have a garden-variety
cankerCanker sore
Canker sore (aphthous ulcer)
Canker sores
Fever blisters and canker sores sore, not syphilis. In general, the chancre of syphilis is painless and has a firm, "solid" feel to it (often described as "rubbery").
CankerCanker sore
Canker sore (aphthous ulcer)
Canker sores
Fever blisters and canker sores sores generally are "soft", not firm/rubbery, and quite
painfulPainful menstrual periods.
Anyway, 11 weeks is long enough to be considered
reliableReliable gentle laxative, even if a bit short of 3 months. But if the lesion is like my description of syphilis, or if you have reason to believe the person you were exposed to actually has syphilis, follow up with a health care provider for further evaluation.
HHH, MD