AF due 3•30!

So AF is due 3•30 & this morning when I peed and wiped it was brown with a little bit of pink, it was like this all day. I had my Mirena removes 2•12 & my first period 2•27-3•3.  Do you think this is implantation or do you think AF is coming ?! I ovulated with "peak" ovulation days till 3•20. My calendar doesn't show that. Help Please! Thank you!!