Early Pregnancy Symptom

Let me start by saying that I have PCOS and have always had irregular periods. In October I took Provera to induce a period. Since then, my cycles have been between 21-23 days. (I only took Provera that one month). 
I'm on CD 25 and today I had dull pain like in the middle of my chest for about 10 minutes or so. Now I am having dull pain in the bottom of my ribs. 
I have tested the past 3 days and all have been BFNs. 
Has anyone experienced those pains as an early pregnancy symptom?