There are several possibilities- a gestation sac in the uterus without any yolk sac
visualized, a twin sac, an ectopic pregnancy
, an ovarian cyst
and an intrauterine sac or simply, some precautionary measure. Some cramping is observed in early pregnancy as the uterus enlarges, but tenderness and vaginal bleeding or pain on intercourse suggest the possibility of an ectopic. Please wait for your results and see your doctor. Meanwhile take bed rest
, avoid stress and intercourse. Wish you good health.