How can you tell the difference between IB and AF?

KaShaun
So today I had light cramping and wiped and saw blood. AF is due Monday but I tested anyways and of course I got a bfn. So now I'm worried that AF might be coming early. What are some differences between IB and AF? Smell color idk I'm nervous I would love to tell hubby we are pregnant for Christmas. Baby dust to you all 🌟🌟🌟🌟