Bfn .. ?

Stephanie
So my story. 
Last period was 28th of April lasted 4 days. Periods are usually very heavy the first day. Cycles are 30 days sometimes 32. 
This month I had very light bleed on the 18th. Didn't need to use tampon. Next day it turned to brown cm. 
since then I have had sore breasts, headaches, nauseous without vomiting, on and off for the last few days, as well as I have had pink cm for 2-3 days now . Which is when I should have started my regular period. 
Could I have had a very very early period and am now ovulating ? Or could I be pregnant? 
Also took a test on the 27th (doctors office ), and 1st (clear blue digital) both were bfn . :( 
Had anybody gone through the same experience ?