The plastic bag mystery was solved when MultipleMum from And Then There Were Four left a comment! Thanks! It was slowly killing me thinking about it. As for the plastic bag challenge - I have only had one bag come into the house and that made it in by me being unprepared. Actually maybe the count is 2 as Dave let the butcher put our meat in one. So yeah two. I have had to send Dave out to the car for our reusable bags and on one occasion we carried our groceries in our arms to the car! Thankfully it wasn't too many!
I have got the bags permanently in the car as well as carrying an enviro bag in my purse all the time. Its working.