Has rpr ever turned positive after the first 6 weeks? i see online that a 90 day test is conclusive, but i also see that 6 weeks is conclusive. which is it? how often do people get diagnosed 8-12 weeks after potential exposure, but not the first 6?

A negative test after 90 days is conclusive and we do not use this term "conclusive" for a positive RPR at 6 weeks post exposure. So, when a screening test such as RPR is positive after 6 weeks we don't say if the result is conclusive or not but we proceed to the next step for confirming the infection , i.e. TP-PA test should be done.

If the RPR test result is positive, it is conclusive at 6 weeks or even sooner. To conclude that a negative result is real you need to test at 90 days after exposure. For info: Syphilis window period: https://www.e7health.com/post/155/std-test-window-when-should-i-get-tested/#:~:text=The%20average%20window%20period%20or,it%20develops%20in%20three%20stages. https://www.cdc.gov/std/syphilis/stdfact