Am I pregnant ?

Hey y’all, I have some questions for you ask because my body has been off but I keep testing negative. So I haven’t had my period in two cycles , but I have taken pregnancy test. They have all come out negative, however I feel nauseous in the mornings, my nipples are darker, I have a small linea nigra, and I have this need to pee every 5-10 minutes. My body has been super off. Is it possible to have the hook effect ? I did take a blood test 3 weeks after intercourse but I heard it’s possible for a blood test to come out negative as a hook effect