I have done stuff like that before. Depends on my mood- if I felt impatient and the world pushed me over the edge. lol Don't sweat it- and glad you got your personal stuff elsewhere.
And don't be shy buying stuff- just have fun looking at the cashiers feel embarassed to have to ring it up. lol
I kind of had this experience not too long ago, I'd been to a chemists when I went into town and then on the way home I remembered I had to get something else from the chemists and when I took it to the till the guy, I think, thought he was being a little smart and perhaps figured I'd not worked up the courage to approach the till with it before and was like loudly "so, you got room for that in your bag there or do you need a bag?" and I was like no, its fine and just carried on with the transaction.
I always try to recall the episode of the Simpsons were marge tells homer while away on a holiday to mexico that she doesnt like to think what he has planned because he has bought all this stuff at the local shop working up the courage to ask about contraband, I think its prohibited fireworks, and its like a porn mag, condoms, enemas, choclate cigars.