Aching Ovaries - Could It Be An Std Very Light Period With Different Smell?

Very light period with different smell? - aching ovaries - could it be an std

My time is always irregular (I PCOS). My breasts are probably sore two weeks before I started to bleed. I also had a slight pain near my ovaries as usual. The first day I have in a plug and there was virtually nothing in it. On the second day the same. On the third day was a little in the buffer. The fourth day, the same thing. The fifth day after the urine dark brown (almost purple) in the tissues and the smell was terrible! Almost felt like something dead. I've never felt anything so badly before! (Yesterday and today said the sort of thing but the buffer zone has never been covered, wet or something ... it is not normal for me). Today, not with a tampon, because I thought it was over, because it was so clear.I'm sitting here and I can smell the smell again through my pants. What is it? I'm sure they have a sexually transmitted disease or something, because I have been checked.