Sis, normal yan sa pregnancy, yung ligaments mo (round ligaments) lumalaki at nag-aadapt sa baby, kaya parang nahuhulog or naghihila talaga ang feeling, lalo na pag nakatayo ka ng matagal like sa work mo! A few of us moms noticed the same thing around that time, especially kapag busy shift or standing all day. Try to sit down and rest pag pwede, wear a maternity support belt kung kaya, at definitely mention it sa OB mo sa next check-up para peace of mind lang, just to make sure everything's good. Take care, momsh!