I am currently on my menstrual cycle which is almost 2 weeks late and i've only been on it since sunday. When it started, the blood flow was very light and a brownish color(like old blood), the next day was very heavy flow with severe cramping and then last night the bleeding stopped, I started back bleeding today and a few min ago i went to change my tampon and pulled out what looked like a mucus plug with the tampon and my flow is very light again. I have never had a cycle like this. My tubes are tied so I can't be pregnant can I? What else can this be?