What does this mean?

It is my 3rd day of bleeding. (13dpo)

Not sure if it is period as it is different to how it normally is. It is bright red and thin. Also have bad abdominal pain, left and right side sharp pains, back pain.

And today i have stabbing/burning in my left breast. I never have pain in my breasts.

Does anyone know the reason for this..?

*also getting alot of heartburn.