Can lifting and carrying my wrigling tantruming todder be dangerous when16 weeks pregnant with twins?

when my boy is well he is an angel and will do pretty much what he is told and walk everywhere.when he is poorly or teething it is constant wanting to be carried,picked up,tantrums if i dont in shops ect.wont alk up front steps or stairs which can take half an hour to just get from front door to car if i didnt lift.so i end uplifting and carrying.i somtimes feel pain afterwards and pressure down in my cervix area.are my baby well protected or am i causing damage?