The pill....

Question......Ok so I started taking the pill for the first time when I started my period again about a month and a half ago and I didn't miss any pills the entire time. About 4 days before I was supposed to start my period again I had dark spotting and it was only for a day. When the day came that I was actually supposed to start, there was nothing. So my question is, does the pill mess with periods and does the dark spotting count as my period or could I possibly be pregnant.... Kinda worried but want to here of any similar experience before I take any test.