breakthrough bleeding/spotting

I am on the pill (Portia - a generic).  I have been on it since July (so its not like my first month or anything).  But this pill cycle I have had some weird spotting.  I got my period during the pervious placebo week (it only lasted 2 days but was a pretty normal flow those 2 days).  Then at the start of week 2 I had 2 days random spotting.  Now, near the end of week 3 I have spotting again.  Coinciding with the spotting I am also having very light cramping, but its like it will flair up for a moment here and there, not really consistent like period cramps are.  Anyone have a clue?  I am between health insurance plans now, so I really dont want to consult with a doctor, and I am not worried so much as curious at this point... 

I always had wierd stuff like that when I was on the pill.