vaginapagina | Period or Infection or Breakthrough Bleed? (Reply)

I started HBC (Loestrin) on the 10th day of my cycle using the quick-start method. I will take my 16th pill in the pack tonight. (This is day 25 in my cycle; I have a 30 day cycle.)

In the past day or two, I've started noticing some brownish discharge. It looks a bit like the discharge that comes on the last days of my period. As far as I can tell, it doesn't have any strange odor or texture.

I don't know whether this is a period (I would normally be due a week from now, on 5/6), a "breakthrough bleed," or an infection. Are there signs I should be looking for that would help me identify which it is?

I've been feeling lethargic and moody and headache-y, which does happen to me during periods, but this is a relatively slight discharge compared to the bleeding I usually have.