First time out without baby

Juliana
Today, while my two week old napped, my mother and I quickly ran out to pick up his birth certificate and prescription to treat his thrush. My sister stayed with him and we were out for less than an hour (he was even still sound asleep when I returned), but the whole time I was out I felt guilty for leaving him. It even seemed as though every cart at Target had an infant seat in the basket or an expecting mommy pushing it. I know hormones are still crazy and I don't plan on making this a regular occurence but I wonder if this feeling will get better in time or will I always feel bad leaving my LO?