When you took the second test an hour later you probably didn't have enough hormone to show up.
If you are not using first morning (overnight in bladder) urine, you need to make sure it is at least 4 hours old (in bladder) and that you haven't have an excess to drink (will flush and dilute hormones)
positive tests are rarely wrong negative ones can be wrong.
Even a faint line positive is rarely wrong (maybe be faint because urine not strong/old (in bladder) enough, very early in pregnancy etc)
my advice would be to either take another test (making sure the urine is strong enough) or pref get a blood test.
If you don't want to be pregnant you need to find out fast so you can consider your options if you are pregnant and it does sound as if you could be.