Hi My Girlfriend Used Nordette As Ecp Sept 12 Then

Hi my girlfriend used nordette as ecp sept 12 then she had her period sept 15-18 and then we made love again and took ecp again last october 6 cause we check the in the calendar that she is fertile during that time (we used the withdrawal method).She had her period october 22 lasted 4 days it stops and she had a spotting .. is she pregnant or is it the hormones from nordette? Thank you