what kind of cramps? if they are gentle cramps then i would say its probably ok, i had cramping early on in all 3 of my successful pregnancies, if you have any bleeding and the cramping is bad then it could be another miscarriage, seek medical advice if you are bleeding and there is alot of pain.
good luck :)
I have one baby (only tried once, so I'd say it was successful :)) and I had cramps from about 5 wks to 7 wks with brownish and pinkish spotting. I was terrified, because the cramps were like menstrual cramps in my pelvis and lower back. I was such a pain with my OB that she agreed to do a sono at around 5w5d and there was a little heartbeat flickering away. She said it was likely implantation bleeding and to monitor it with cautious optimism. I did, and Nathan Joseph was born 7/5 at 9lbs! Definitely demand a sono, if you can, given the history of m/c. If you can't get it with your OB find a clinic to do it. It's better than wondering, at least it was for me. Best of luck to you!
i had pretty intense cramps that early on- they felt like menstral cramps but much worse. lasted several weeks, and i lost a lot of sleep from the pain. dd is now 3 months and i'm losing even more sleep. :)