Light brown spotting

I have light brown spotting for week now. My period didn’t start yet, should start next week.

I only had protected sexual contact (condom+pull out combined, I hope you understand). I don’t feel bad. I had similar situation in October but my period started in 3-4 days after spotting... I’m nervous so much. What can it be... may it be something due to my irregular schedule or weight loss maybe, or stress...? I’m sure that condoms didn’t break or anything... scared a bit