That was way too early to test. You'll need to wait and repeat your blood test in 3 or 4 months to get more accurate answers. That was even a few days too early for the bacterial std's too.
It's a really low positive and it needs confirmed ( fairly decent risk of a false positive with results under 3.5 which is why additional testing is needed ). Since the last time you had sex
was recent you might as well just wait and repeat the blood test in a few months instead of wasting time now confirming that result and then only having to repeat the test again in a few months anyways.