Counting Baby Kicks

Over the last couple of months, my OB-GYN began each visit with the question “Is the baby moving okay?” At first, I wasn’t sure what she meant and how to answer. I thought the baby was moving from time to time, but I was not sure. Plus, I didn’t know what was considered normal. Was I supposed to feel him kick at any particular time of the day? How many times were considered sufficient? How strong should the kicks be in order to count?