HELP!!! BFN & Implantation Spotting?!?!

Kelly • Married. 4 years TTC #1. VA🍍. PCOS.
Ok so needing some relief (if that's even possible during the TWW). This is my first cycle combinging weight loss (10 lbs gone woo hoo!), metformin, and a new diet/vitamin mix after a recent diagnosis of PCOS. 4 + years of TTC has me conditioned to expect the worst/least but this cycle is unlike any other I've had while TTC. 
Sooo on the 12, 13, and 14 of this month I had what I expect was implantation spotting (for the record I feel like I'm grasping and hoping - but at the same time, I can't ignore what I saw). About 5-7 days prior I think I ovulate (never experienced this before). I had a pinching in my left ovary for 10-15 min one night followed with 3 days of spotting only when I wiped. I BD during that time. A lot lol. 
Implantation bleeding? was the same thing. Very light pink/brown discharge when I wiped only. TMI. Sorry. 
STILL getting a BFN though! EVEN with a FRER. No AF but I can't rely on AF as I do have PCOS which throws me off sometimes. If I was on a typical 30 day cycle (like I used to be) I am officially a day late. But I can't be certain. 
I have been nauseous with exhaustion and mild headaches and dizziness. Smell is HIGHTENED to say the least and I cant stomach the thought of eating hardly anything. I'm irritable because of it all and the TWW certainly doesn't help! Don't know if this is the metformin maybe just now effecting me more? I've been on it for a month though. 
Any experience with any of this is helpful! Late BFP? PCOS? Metformin? Implantation? Ovulation symptoms? I'll take any of it!!
*dust*