First, i would like to appreciate your honesty and concern for wife's health.
If your are worried about HIV infection. You can go for the PCR technique to identify HIV infection. It will show result in 2 and 3 weeks after exposure.
For other STDs, you can see the symptoms from day one of the exposure to 3 months and more. There are lab tests done for other infections also, which you can do, to rule out any STDs infections.
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