My fur baby!

Katie • My husband and I have been together since August of 2013. Got engaged December 2013 and we got married July 26 2014.
My dog is 2 1/2 years old Shiba inu mix, he is fully potty trained but this week he has went to the bathroom in the house twice! Idk why we've went months without an accident and this week Second accident... Any one have any advice or ideas of why?