Is it Implantation Cramps or ..........?

It could be implantation cramps but there is no true way to tell. Some women test early and 10 dpo is not a bad time to test. If you do get a negative at 10 dpo, your body may not be producing enough HCG at that point and you should retest a few days later. I would say take a test when you are ready to. It does sound promising but it could also be nothing. Some women take longer to implant, anywhere from 6-10 and some even longer. I was one that took a little longer!