Is it possible that implantation bleeding (9dpo) come after whitish discharge or leukorrhea (7dpo) ?

Possible? Yes, but..: A positive pregnancy test can tell a woman that prior spotting was actually implantation spotting. It can be hard to tell if a woman is pregnant because some of the symptoms seen in early pregnancy can also happen in non-pregnant women. A urine pregnancy test gives a reliable result about 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a period.