24wks preg.from 4days back feel abdominal cramps and discmfrt.scan normal.but i can't walk up to 10 meters due to discmfrt.no infections.why so?worried

Round ligament pain: You may have round ligament pain, which is common and normal. If the pain tends to be more one sided, worse with ambulation, lower towards the groin its usually round ligament syndrome. Preterm labor on the other hand won't necessarily resolve with resting. Some Acetaminophen and rest usually resolves round ligament pain.

Probably normal: By 20 to 24 weeks the uterus is large enough to cause extensive stretching of the round ligaments and increased pressure in and on the pelvis. That would result in varying degrees of pain and discomfort. The hips begin to change orientation due to changes in the pelvis - that causes hip and thigh pain as well. All of that is common and normal in pregnancy. Sometimes physical therapy can help.