Hi,
Welcome to the ehealthforum. I am glad to help you out. You are absolutely fine. Most of the women suffer from abdominal cramps at the time of the menstrual cycle, especially during the first 1-2 days. However, it is not a must to have cramps every time during the periods. Hence, the periods can happen without any abdominal cramps. Thus, everything is okay and you need not worry about the same. I sincerely hope that helps. Take care.