I Was Either Bitten By A Spider/bug Or Have Something

I was either bitten by a spider/bug or have something like shingles. started with one spot on inside breast and now have 8 spots circling around my left side to middle. they itch. also having sharp pains from outer left breast towards middle. pain last 3 or 4 seconds but takes my breath. no other symptons. been taking Tylenol arthritis pain reliever. happened Thursday afternoon and today is sunday. do I need to call my doctor tomorrow?