Hi, I Had My Last Menstrual Period About 1 Weeks

Hi, I had my last menstrual period about 1 weeks ago and yesterday I started having a thick, dark brown discharge from my vagina. I initially thought it was irregular bleeding or spotting, but the amount eventually was enough to require me to insert a tampon . After removing it however it seems more like an odd discharge than blood; it was covering the tampon but didn't seem to have been absorbed at all. It has a thick and pasty consistency but does not have a foul odor nor the odor of blood, or really any smell at all. I've looked at those symptoms online now but couldn't find any likely cause (that I know of). I have no other symptoms, i.e. cramping or signs of infection, etc, so I'm pretty please help