You are completely fine...
1. its ONE vial of test... the absolute worst case scenario would be them confiscating it and sending you a letter that they are keeping it but thats so damn unlikely
2. you are not on anyones radar whatsoever as a small consumer... you are insignificant as it gets to them
3. domestic supply ships domestically so that even makes is less likely of any issues but anything is possible however i outlined what the worst case scenario is
you are severely over worried and if really causes you that much stress, just dont order or send it to someone else