I feel your pain - this is my 2nd IVF cycle and it is a lot harder to feel optimistic. I did talk to my RE's office 4 days after my ET and they said that cramps were normal. I think this early, it is too difficult to really judge what anything means as it all could be a side effect of the progesterone.
I'm a beta or bust kind of girl so I can't tell you about testing. If I were going to test though, I may just test the day of beta so I'm prepared for that phone call.
Good luck!