Help! Stressed and confused

Is it possible to experience pregnancy symptoms before implantation?? My period was supposed to come on 3/16, I had very sore boobs and light cramping and took a test on 3/21 that came back negative. I had protected sex that day and I’ve been bleeding a little, I don’t know if it’s spotting or my period being light, which I’ve never experienced. My breasts aren’t sore anymore and I do have cramping like i would get while on my period. Could it be that my period is very light because of the stress and anxiety about an unwanted pregnancy??