Could I be pregnant?

Today is 12Dpo and AF due on 25 June. I have been getting symptoms like nausea and fatigue since 3 days and I had started hoping that this is the day I have been waiting for but...this morning I got brown spotting. Very very light and now nothing...

Could this be implantation bleeding or AF?

Is it too early to take a pregnancy test?

Anyone has been through this? Please share your experiences.

I am 33 years old and TTC since 7 years.