Jeff White gives guidelines in this video about bed bug bites.
The first thing is that bites will show up in clusters or rows. They feed at night and it takes 5 to 10 minutes to fill up on a blood meal. That is why there are rows of bites or a cluster.
The second thing to know is that typically the bed bugs bite exposed skin surfaces. The bites show up in the morning.
The third and last thing to remember is that not everyone's body reacts to bites in the same way.