late and bfn..

I had taken a test last month which came out negative and then got my period, everything was fine for the month but now I'm 3 days and still bfn. 

As much as we are trying I was okay with he first negative as oh is in the army and wasn't convinced he had been home at the right time anyway. Now that I'm late it's skewed all calculations and not sure if I will get my chance this month!

Any guidance or help is greatly appreciated!