Help! Late period- BFN

I am 13 DPO, 2 days late with AF. I've tested twice.  1st test was a faint line. But I think it was an evap; not quite sure. second test I thought was Negative. Posted it up In the Faint Line thread, people said they saw a line  (I didn't see anything).  I'm now 2 days late. With cramps that come and go. Not like my usual AF which JUST stay and get none stop. Not sure what to do. Anyone have symptoms?