Implantation bleeding or stress spotting?

Hi, all! Who has experience with implantation bleeding and can tell me when it happened for you? We haven’t been trying, but on Thursday I had very light pink/brown discharge when I wiped and it also happened once on Friday. Then yesterday, I wiped and it was pink (but a bit more), but not enough for a pad (barely enough for a panty liner). Today I have no discharge at all. I’ve been stressed lately about some personal things, but it’s since been resolved (yesterday late morning). Since then, I’ve felt less stressed. I’m due to start my period this Thursday (Aug. 26). I’ve read online that implantation bleeding happens a week earlier (approx) than your period. I didn’t have this with my first child, so this is new to me. Over the past few days, I’ve felt nauseous on and off, had some light cramping in my stomach, had adversions to certain foods, etc. But I also know that can be stress-related. I took a test on Friday evening (even though I knew it was too early) and it was negative. I plan to wait to see if I get my period later this week. Any insight appreciated. Thanks, ladies!