Recently I have made tooth surgery , tooth removed and stitches done, I had lot of antibiotics,after a week  my semen is in slightly brown color, before 1.5yrs I had a similar problem even slight blood has come, and after tablet prescribed by doctor it has cured, now after 1.5 years again my semen color change into slight brown, is it infection ? No pain in ejaculation or urination ,urine found normal,  also I suffer from acidity . slightly worried about the change in color of semen, kindly suggest.