Pain- 5 Weeks

Hi so im 5 weeks pregnant, i went to the gym today and i did 40mins-4ks on the treadmill as i was walking out i felt such a sharp pain in my abdomen and then i felt dizzy.. im kind of worried...has anyone else had like a sharp stabbing pain and felt a bit dizzy and been okay? i have read it could be round ligament pain..but not sure ??