Most people do not know that they have been exposed to bed bugs until they start to see or notice small round bumps, which resemble those of mosquito bites. These bumps will tend to be in groups and clusters, or they may even look like they are in a straight line or run along your veins. The bumps start to appear within 24-36 hours of exposure, so you can attempt to retrace your steps to see how or where you may have been exposed. Another sign of bed bugs is that you may notice blood stains or spots/streaks on your sheets when you are making your bed. You may have stayed at a hotel, stayed with someone else, or someone stay with you, it is that easy to unknowingly expose yourself to bed bugs.