Help with depo and cm?!

So I had my last shot of the depo on the 19th September and I didn’t go back for my next one on the 19th December (purposely) I had brown/reddish spotting over Christmas time and then nothing but I got this time today, it’s more of a pinkish colour in person and when I wiped it was pink/brownish watery type thing. Could any one please explain what this means