Hi and thanks for the query,
Its actually too early to start expecting clinical signs and symptoms of pregnancy
at 6 days. However, the commonest cause of lack of seeing periods in females of reproductive age, especially those having been exposed to unprotected sex during the fertile periods of their cycles is pregnancy. Mild pain or implantation
bleeding might be observed as you described any way. The pregnancy tests
used however become positive only after 7 days after implantation. It be reasonable for you to be patient a bit and do a blood pregnancy test, Beta HCG
levels which is relatively very accurate. Pregnancy is a possibility, but expecting clinical signs of pregnancy as early as 6 days might be too early. Consult your primary care
physician for pregnancy testing.
Thanks and best regards,