Please help me work this out!

Madeleine • 21, just here to keep track of all the things, y`know?☺️💕💕
This may be a little TMI, sorry in advance, but I need answers. Okay, my last period started 30th Jan, basically about 4 and a bit weeks after my last one. The only difference is, I started on the proestrogen only pill on the 11th of January. I was warned that it can give irregular or no periods. So my last period came and went, it was lighter throughout than previous periods and lasted like a day longer than normal. It finished on the 8th of Feb. I've been spotting since Friday, and then today, it seems like my period has started, only two weeks after my last one ended. However, the discharge doesn't look like period blood, it looks like the kind you get toward the very end of your period, all brown and stuff. So I'm confused. It would make sense if this was my period, because that would be irregular as hell, but why is it so light? My last period was completely the same as all my other periods, just got lighter earlier on. Please just so I know what's going on! Thanks :)