16dpo

Hi guys! I'm new here, I need some help! I'm 16dpo, yet I tested about 2-3 days ago and got nothing. Now my period is late it was supposed to start 2 days ago. I've had tenderness in my breasts, nausea, headaches, etc. I did have unprotected sex around that time. I am not sure what to do. Any help would be appreciated!!