Welcome to the Forum.  I'll try to help.  The risk of the exposure that you describe is low, based on your description of your partner, that she told you she had been previously evaluated and was negative and, implicitly, by the fact that you were using a condom (suggesting that you both were committed to safer sex practices).  Unfortunately, the condom broke and so testing is appropriate, just to be sure.  so, IF she was infected (unlikely), how high is your risk?  Low.   Remember that most STIs are not transmitted with a single exposure and that for HIV the risk for infection is, on average, 1 infection in 1000 exposures, IF your partner was infected.  For other STIs the risk of transmission would be higher but still relatively unlikely, being in the range of a 20% chance of infection if your partner had gonorrhea or chlamydial infection.  Thus, on the basis of these figures, your risk for infection is low overall.  Nonetheless, testing is reasonable.  For HIV, the 4th generation tests give accurate/reliable results at 4 weeks/28 days and at 15 days would detect most but not all recent infections but precisely what that proportion might be is debated.  Certainly most however.  The RNA PCR tests are not much better than the 4th generation tests and really do not add assurance sooner, despite what those who sell them will tell you. 

In summary then, this was a low risk exposure.  The likelihood that you were infected in tiny (probably less than 1 in 100,000) and the risk that you infected your wife lower still.  My recommendation however would be to wait until 4 weeks for testing for the complete assurance you desire.  I hope this comment is helpful to you.  EWH