Totally no idea

I don't know what is happening to me. Last period was on 7th of Feb and expected to be period again on 14th of March. Been Spotting for 6 days (12 days before expected date AF) and until today, my AF hasn't show up. Out of sudden, I got sharp pain in my lower abdomen, just right below my belly button and short of breath after walk to toilet. I have tested last on Tuesday but got BFN. Has anyone here familiar with what I am going through right now? Thanks in advance 😊