What Causes Brown Discharge,light Spotting And Bad Odor During Periods?

I am prementapausal and have had a period for a month and a half. This has happend before but this time I have a brown discharge along with a little blood and a BAD odor that smells like something is rotten. I checked for a tampon but can t find one. I am wondering if this is a normal mentapausal symptom?