13 dpo

so...I took a test this morning, the cheap ones from amazon and it was BFN. Ive been feeling like I have my period, litteraly getting period cramps for 2 days straight but no AF yet. I feel nauseous this morning but i feel like its caused by the pain of those bad cramps .... Im a out? If you get a BFN 13 dpo, are u likely not pregnant?