Cramping and sore breasts 10dpo

My period is not due until Saturday (4 days away) and I'm experiencing some pretty intense cramps and very sore breasts. I am 10dpo (I didn't ovulate until day 18 according to my opk test)....we have been TTC for 11 months now. I typically don't get cramps until a day before my period. Could this be implantation?! I'm driving myself crazy and want to take a test so bad but I know it's way too early: (