What Causes Black Scabs On Abdomen, Thighs And Arms?

I was in the bathroom on Saturday lifted my shirt and there were quite a few small black raised scabs on my upper stomach back of one of my arms a few on my thigh! Some had redness around them and had red marks that turned into scabs rapidly! Went to the hospital and they said they don t think it s bedbugs but didn t know what is was! It doesn t itch! The next day, much better. There are some still on me but smaller and seem to be disappearing! Just now, looked and now they are on my chest, Shoulders and a couple on my back! I have am appointment with a dermatologist tomorrow but they are going to call me because they might not make it in because of an incoming snow storm! Help!!!!!