missed pill?

So get this I wake up everyday at 6:30 am and take my pill. If I have nothing else to do I will go back to sleep. Yesterday I woke up at 6:30 got up and took a pill (or at least I thought I did.) I suppose I was dreaming. On Saturday I had took my first pill of the third week and on the same day noticed some spotting. I asked about this and someone told me it was normal. Yesterday, the spotting turned into a light period flow. I was wondering if I messed everything up? Today I doubled up on the pill since this app said to. 
This is my first time on BC, so I was just wondering if this is normal to start your period early on the pill or is my body just getting use to it?