Ok moms.. I keep a period tracker on my phone and it shows the date I'm suppose to start my menstrual cycle but for the…

Ok moms.. I keep a period tracker on my phone and it shows the date I'm suppose to start my menstrual cycle but for the past year I have been getting it 3 days earlier than the date. I had my last menstrual cycle March 10 but I was suppose to start the 13th . Now it's a new month I didn't start 3 days early this time and I'm one day late. I started bleeding lightly. Could it be implantation bleeding? I'm not sure because when I was pregnant with my daughter who is now 4 I never had any implantation bleeding so I'm not sure what it looks like. I've also had quite a bit of pregnancy symptoms for the past 2 weeks.. pls help. Thank u