HELP PLEASE

Alright so this might get graphic. My boyfriend and I have been together a little more than 6 months. In mid-October I had weird symptoms. I thought it was a yeast infection but OTC treatment failed so I went in to see my gyno.. we tested positive for chlamydia.. he got it from his ex because I had been tested for my yearly just a month before we got together, and he's been my only partner since. Anyway! I had just gotten off of my period when I got the meds to clear it up.. so then my last period in late November, wasn't really a period? Like.. I had the same symptoms I always do, I had cramps, blah blah blah. But the discharge was that weird dark brown (which I know is old blood blah blah blah) and very little red. It was an extremely light period- almost nothing. And it only lasted a couple days. Now this period- I'm supposed to have started yesterday(my pill stops on sundays but I don't start til wed-thurs) and I have that weird brown discharge again.. idk what to do. I looked it up.. I shouldn't be pregnant because we haven't been active other than twice last month and we were safe+birth control. With all the stuff going on, we never get intimate anymore.. after the whole "std situation" he rarely comes near me because he feels bad about it.. I reassure him that I love him and it's 100% ohkay, it's curable.. things are tough... I know stress can mess with periods too... help girls, please! What could be the cause of the weird, extremely light, short, "brown" ish periods?....