Pregnant? Ineffective birth control? Help?!?

Ok this is my 7th day back on birth control in over 6 months. I skipped a pill sunday but doubled up monday and have been fine until i just went pee and i'm spotting! I spent 3 days at my brother's house helping care for their newborn and even developed a little milk leakage though i haven't breast fed in over a year. but asked y!a and found out that Could be normal hormones from caring for a newborn. Am i spotting because that pill i had to double up 2 days ago? or is there more to this?