Confused and Over It

I have hypo thyroid and hoshimotos (thyroid auto immune disease). My periods have been like clock work since I took my Mirena out in Feb 2015. Even when my TSH has been sky high it has never affected my period. I have been trying to conceive for 5 months. Periods have still been regular. I am now 12 days late. Two negative at home tests and a negative urine at the dr. Has my thyroid finally caught up to messing with my period? Dr was absolutely no help.