Rash Spread Throughout Body, Itches On Certain Area, Looks Like Bruises. Taking Medication. Any Ideas?

I have a rash that has spread throughout my whole body within the pass few weeks. They don't look like shingles because it's not just in one spot. They are not itchy nor do they hurt! Sometimes, they my rash itches on certain areas but they don't hurt. They are small, pimple like rashes. Some are bigger than others. Some have also turned into small blisters almost, they have a little scab on them. Some have turned into dark spots, they almost look like bruises. My doctor said they were hives, which they somewhat look like hives. But they haven't gone away with medication. They are just turning into a darker color now! I don't know what it could be. I haven't exposed myself to anything new besides different medication.