Hi I have been on birth control, sprintec for about 8 months, I had my period on my placebo week, and havent had any refills, I have not had sex since then, but I saw some blood today (the next friday) - not spotting, but a good amount. should i be concerned? is this because i stopped birth control or is it somehow indicative of a period (within one week of ending my last) or being somehow pregnant?