Hi, and thanks for your query on eHealth forum!
Cramps do occur in pregnancy. Gas in abdomen is the usual cause and these cramps are usually mild. Period like cramps could be a sign of threatened abortion. However, cramps could also be a sign of ectopics, polycystic ovaries, IBS, Crohn's, pelvic inflammatory disease and similar conditions. Appendicitis causes pain that comes and does or may continue. The only way to confirm is by ultrasound of abdomen. This is quite safe in pregnancy. Do discuss this with your doctor and get yourself examined. Take care!