I didn't think I was pregnant at all this time! With my three miscarriages, I had pinching pain when I think I implanted, really sore boobs, and cramping before a BFP. This time... I didn't get any of that. I only tested at 10 dpo cause I figured why not, and I was shocked when it came up positive.
So I think sometimes there are symptoms, and sometimes there are none before a BFP.
Good luck!