I went for the test 27 days after exposure. The results say .10 value where .90 or over is positive. IgG value is .10 - negative. Can I be certain that his is correct and I do not need further testing.

No.  27 days after an exposure is too short.  If you test negative on the IgG test at 6 weeks out from the exposure, there is a 70% chance you will stay that way.  And there is a good chance of a false positive.  This test is not recommended any longer for screening due to the high rate of false positive results.---