Skin lesions and rashes are very hard to diagnose without actually being able to see the lesion, especially in the absence more information that is generally gathered when you visit your doctor
. Small circles of bumps that are itchy and seem to grow over time could be the classical ringworm (tinea corporis) that is incredibly prevalent. If you are caring for young children, it is possible that this fungal infection was spread to you in that manner, but it can be passed even without small children, obviously.
The interesting thing about your personal case is that it seems to have improved with the use of calamine lotion, which is used to help decrease itching. The fact that it improved as the itching improved could indicate that it was just some sort of local inflammation caused by either exposure to something that you are allergic to, or even just something as simple as a pimple or bug bite that you kept scratching and it had just a very small infection.
If the circles are gone and you have no other symptoms, than you are probably just fine. Worms, bed bugs, and monsters that you mention in your question are all highly unlikely. Please see your primary care doctor
or a dermatologist
if you have further questions or the bumps return.