Cramping

So I am 5 weeks pregnant. I had mild cramps (way milder than period cramps) on my lower abdomen. No spotting or bleeding whatsoever. I have talked to my coworker about it and she said I should call the doctor because there could be something wrong. This is my first pregnancy and I have heard different opinions--one says it's a good sign and some say it's bad. Now I'm like clueless. Not scheduled to see my OB until October 3. What do you think? Any comforting words or advice?