so confused! 😔

So my OB Dr. Put me on metformin 500mg 2 times a day in September. Here lately I have been super nauseous especially at night, my boobs and nips are super sore but every pregnancy test has came out negative. My hubs and I have been ttc for almost 5 years. October 11th or 12th I spotted for only a few minutes. And last
Night I was spotting light pinkish. I've had irregular periods since the age of 13. I'm losing my hope and faith with each negative test!