Spotting is normal in Diane-35 if taken late last month?

1 year User na ng Diane-35 taken right time and period is @normal cycle.But last month halos kinabukasan ko na lagi naiinom.this month spotting lang and late na nga ng 2 day tapos spotting pa in 3 day iba iba,may brown,light red after 3 day nawala na ung spotting then after 1 week kapag nagbubuhat ng mabigat or napagod gaya ng buhat ko baby kong 2 yrs old nagugulat nalng ako may spotting.ulit am I pregnant? or is this normal