Help! 9days late, BFN and cramps. Am i pregnant?

Hi everyone,

I normally have regular 28-30 day periods. This month im on day 37 since last period. I tested couple days after missed period and got a negative. Have tested since last BFN 5 days ago. But ive been crampy since before AF was due. Now I'm still crampy, late but having negative tests. No sore breasts or any other symptoms apart from slight nausea now and again. I had a chemical pregnancy in October last year and really want to be preganant  any advice or thoughts?