HEEELLLLPPPP!! was this a missed period?

So I've been on the pill for about four months. The first too months were sample packs from my doctor. The pill is loestrin and it made my periods super light (yay😊)The third was a generic version. My period was almost as heavy as a normal-not-on-birth-control period. 
This pack I just finished was the loestrin again. ( I was on the generic because I had to wait for my insurance to cover these pills specifically) 
There are four placebo pills in the pack. My "period" didn't come. Instead this pinkish discharge came on the last day of the placebos..
Is this a sign of early pregnancy, or is this normal because I switched brands and my last period was heavier than normal?
P.S. I take my pills religiously and never missed one😁
Thanks for your input in advance❤️