Lifting heavy pregnant 😕

Ok so, I’m 28 weeks pregnant and usually all the heavy lifting my husband does, he is so scared I’ll get hurt but i get frustrated when I want something done and he’s not around. Just now, i tried to lift a heavy box that was in the way. As soon as i squatted down and lifted it like not even 2ft off the ground I felt some numb kind of pull in my stomach it scared me so i dropped the box immediately,

Nothing hurts after that but I’m scared I’m not sure if this can harm my baby 😞😞😔😔 has this happened to anyone else before ?