41 days in...no AF

So I'm normally like a full 31 day cycle and this month I'm over a week late. Im not symptomatic as much as I would think I'd be. Oddly enough pms has disappeared and instead I'm nauseous and fatigued. My cervix is suuuuper high but yet I've taken a couple dollar pregnancy tests and they were negative. Anyone else experience this or know what might be going on?