I'm 19 years old and I am sexually active with my boyfriend. I am on the pill however I noticed a very light red color when I whipped the other day then it went away. Now it happened again. I have been sick and taking anabiotic's could that interfere with my birth control and cause me to bleed? Or could it be something else I got my period last month and I should be getting it again in a week or more. I just wan to make sure that it is something normal and I'm not pregnant this has never happened to me before. So I am worried what could it be.