I just noticed my Adwords account shows 0 conversions yesterday.
When I go to Analytics and check
Conversions -> Goals -> Overview -> Source/Medium
it says there have been 20 conversions from the PPC source.
I remember there used to be a lag of up to 3 days for reporting to transfer over from Analytics to Adwords but that was many years ago.
Have you noticed anything unusual during the last couple of days?