Sharp pain in uterus?

I am 9-10dpo and a few hours ago I got a sharp pain in my uterus. It was enough to make me bend over and suck in my breath real qiuck. It really wasn't to one side either it was mainly the middle. It happened once more but not as severe. This is not like a cramp either it was like the pain you get in your side from running too much but it only lasted for about 4 seconds.... any advice to what it could be?