I agree with SantanL....you really need to take a pregnancy test. Your body could just be messed up due to missing pills and then taking others. The hormone levels are probably going up and down. There is more of an increased chance of getting pregnant when missing pills. Your body does not have the steady "flow" of hormones and the levels become lower which increase your chances of ovulating. Take a HPT and see what it tells you. Good luck.
Did you get your HPT done?
if you just spotted for couple days, chances are you didnt ovulate last month.
Dont freak out, it happens. As long as its just for few months, it is normal.
If you continue to see this trend, contact your OBGYN
GoodLuck