What Causes Spots Appear On Thigh,breasts And Stomach Area?

Two weeks ago a nickel size bullseye looking spot appeared on my outer thigh. No pain or itching. Live in Oregon, have not been to the woods, can't be a tick bite. Three days ago I started getting small red spots on my breasts, stomach and sides. They have increased in number and started down my legs. They didn't itch but haven't gone away. I take allergy pills daily. I am 42 and have started menopause. Also, when this spot occured I was taking 2000 mg of Amoxicillin per day for a periodontal abcess. Otherwise no health problems...any suggestions?