Unsure..

Treasure
I took a pregnancy test today and Got a positive. Later I had sex with my partner and starting bleeding. Its just a thin line of bright red blood. Is this normal? is this my period starting and a false positive test? <a href="https://play.google.com/store/apps/details?id=com.glow.android.nurture">Pregnancy apps</a> put me just after 4 weeks with due date Aug 11 by the way.