hi renstar,
i can honestly say that i had cramping pains every single day after about 3-4dpo. the pains you describe sound very similar to mine. i would wait untill you are due for your period to test. the waiting game is very hard though! keep in mind that if you are having implantation bleeding then your HCG hormone wouldnt have even started yet! i will be thinking of you and good luck! i have my fingers crossed for you!!!