5 days late with a BFN - normal or not?

So we’ve been TTC for a while. My period is irregular. I’m currently 5 days late with slight cramping, moderate fatigue and dizziness. Could these be pregnancy symptoms this early? I’ve taken a couple tests - BFN. I’ve also heard tests don’t work on everyone. When is too early to make an appointment for a blood test? I’m getting so frustrated. Anyone able to help a girl out?