Still bfn at Day 3 after 5 day transfer/ 8dpo

I'm feeling discouraged, in my last pregnancy (Ivf too) I had a positive today and clearly felt a implantation pain. This time I didn't feel anything and still getting bfn. I'm so sad and afraid it might not be successful.

When did you get a positive after

IVF or just in "normal" pregnancy, if you where early testing?