Am I getting a bfp soon, or premenstrual?

I had an IUI done on 12/26, so I'm 8 days out. Doing progesterone suppositories twice a day. I have felt crampy on and off since IUI and now my boobs are increasingly tender. That happens sometimes though before AF. Is it too soon to feel pregnancy clues? No spotting or any clues from "down under". Keeping my fingers and toes crossed I don't start spotting or get AF soon! Any advice??