I am 31 years old. I have had normal menstration for many years (like clockwork). This month I had a normal period (very predictable as normal). Four days after my period ended I had an allergic reaction to an antibiotic. When I threw up I began bleeding. That was three days ago. It is fresh blood, has stringy material in most of it. And light not heavy. I have no pain odd smells or other symptoms. I have never spotted between periods before. Is this just ovulation spotting or could there be something wrong?