Not everyone is allergic and people have different reactions to bed bug bites. You cannot identify bed bugs by just bites, but they are an indication and if you think you are getting bites from bed bugs you should hire an experienced pest control expert to provide an inspection.
Black spotting on bed or furniture
Bed bugs leave a dark spot when they defecate. It is smooth and black. This black spotting is often found in cracks and crevices of a wooden headboard or bed frame, edges of a box spring, mattress, bed skirt, or the piping or edges of furniture.
As bed bugs grow they shed their skin. They do this 5 times before they are a full adult. These shed skins may be difficult to find but they are definitely a sign that you have bed bugs. The sheds look like a shell of a bed bug and are light tan in color.
One of the most common ways that people identify that they have bed bugs is by finding a bug or multiple bugs. Bed bugs are very light tan when they first hatch and turn a rusty red color as adults. Adults are about the same size as an appleseed.