Plan b

Okay, so i had unprotected sex May 19 and he didn't pull out. So i took a plan b at 7pm on May 20th. I went to the doctor on June 12 for a check up and also had her do a test which was negative but i know that's kinda to early to test. But i only spotted for the first day of my period. Like i didn't need a pad or anything hardly any blood, should i take another test just to make sure I'm not pregnant? If so when should i test? Thanks!