I was wondering why OP is not notified when someone answers his/her question.Same situation happened to me when I posted a question in stackoverflow and waited for couple of hours but no one posted in reply and the other day when I logged into my account I found that my question was answered here.Even some question which I answer the OP responds 2 days later. Here is one such situation
You get notified with a small red icon next to the StackExchange button.
If you want to be notified by email, you need to enable the email notification. You have that option both when submitting the question, and after you have submitted it.