Hello dear,I understand your concern.In my opinion the gestational sac is seen at 5 weeks in transvaginal scan and fetal pole and yolk sac at 6 weeks.They will be seen a week later ie., at 6 and 7 weeks on transabdominal scan respectively.So dont worry i suggest you to repeat the scan after 1 week to see for the progress.The HCG level appears normal.The abdominal cramps along with spotting is seen in case of ectopic pregnancy,miscarriage,thyroid abnormalities,progesterone insufficiency etc.But difinite diagnosis can be made by ultrasound.Transvaginal scan is better for accurate diagnosis.Meanwhile take rest.Avoid physical strain and intercourse. Best regards...Dr.Srilatha