BFN...I think?

Looking for some guidance on this issue. This is my first cycle ttc. Af was due today but hasn't shown and I haven't noticed any signs of it coming (usually I cramp a few days before). I have been having noticeable pregnancy symptoms that aren't characteristic of my usual cycle (sore nipples, fatigue, dizziness, headache, nausea/vomiting). However, I have been getting a BFN everytime I test. I got a faint positive once 3 days ago but I think it was just a dud. Any insight on how long it can be negative and the possibility of pregnancy still be there? Could my hormone levels just be low?