Mirena, where is my period? + neg test

I got mirena inserted during my withdrawal bleeding on placebo pills and my period ended about a day later. I did have sex during the week you were suppose to use a backup protection, I used pull out method. My doc told me it was immediately effective because I

was bleeding, but I now know that withdrawal bleeding doesn't work in the same sense that an actual period for

effectiveness after insertion of mirena. Shame, I was misinformed.

Anyways, that was a cycle ago, and now this app is saying I'm a few says late. Will my period be delayed, or possibly revert back to the way it was before the pills?(My cycles were very long.) Should I test again in a few days? Is testing a day after a missed period too soon?