Pregnancy Symptoms?

Hey y’all! So I switched from the Skyla to the pill in October... I was on antibiotics last month 🤔 the last 2.5 weeks my breasts have been swollen and SO tender, I’ve been absolutely exhausted and my stomach hasn’t been feeling good when I can smell what I’m about to eat. I call my OBGYN last week to see if it’s a symptom of my BC and they told me that my tender breasts could be pregnancy symptoms. I hadn’t put all of my symptoms together. My period isn’t due until this Thursday, but I’ve had dark brown discharge.. could this be implantation bleeding?