What Causes Spotting After Periods While On Triphasil?

Hi yes you can please. I have used petogen for 9 years and I have stopped using it last year in November I started using triphasil from November 2014 till march 20/2015 after my period and my period started again on the 23 then they stop on Friday then on Monday the 06 April I had unprotected sex then the following day I started spotting till today. does that mean I am pregnant???