missed period... bfn

Amber

okay, so I got my mirena out June 5th . immediately ttc, had a normal period on time a week or two after, ovulated on time. but didnt get pregnant. now according to my glow chart, I'm 5 days late on my period... and 15dpo. I took my last test at 12dpo, bfn. any one else go through this? advice? TIA!