LMP May 11, 28 day cycle, pink spotting for a few hours on June 1, period is now a few days late and got negative HPT on 6/8 - when should I re-tes?

Depends. Did you have unprotected sex since your last period? If you did, you may re do the test after June 15. Use first morning urine and follow the instructions for the test carefully. If you do not wish to be pregnant, use contraception all the time, every time. You may consider implanted contraceptive, or IUD. Practice safe sex. Get HPV vaccine.