Ovulation after Miscarriage

Aisha
Miscarriage on 5/19. 
Usually i depend on <a href="https://play.google.com/store/apps/details?id=com.glow.android">GLOW app</a> to know when it my fertile window. 
But GLOW wants me to indicate when is my last period. Pls enlighten me. 
That MC was followed by bleeding. 
Is it period or?