This month my period came a few days later than it usually does, I'm on birth control so I know the exact time it should be coming.. But I got some spotting and thought I was getting it and it never came.. now I just got it and its light, but it's all brown and this has never really happened before... why could this be?

Some women will have more brownish discharge at the start or end of a period... even if it has never happened before. It may be due to the birth control, may be due to hormonal changes, it may even be due to a possible pregnancy. Even on birth control, pregnancy will sometimes occur. You could try a pregnancy test just to see, or wait until next month and see what your period is like at that time.