Need help!

Hello there, I am extremely confused. I have never been pregnant before so bare with me. Me and my husband are trying to have a baby, I could of swore i got pregnant, I had all the symptoms. My period ended up not showing on time instead it showed three days late, for the first day it was extremely lite so first thing to come to mind was implantation bleeding but then on the second day it was heavy with lots on discharge in it then by the fourth day it was completely gone! was that just an odd period or is there still a chance of being pregnant?