20 dpo, CD 47, BFN....what's wrong with me?

-My last period was Feb 21st-26th
- I spotted March 15th- 18th 
-Missed my period that should have begun on the 24th
-20 dpo, cd47, BFNs
-Is there any chance I could be Prego. I don't wanna go waste money on a blood test if I'm not.