24 week pregy
single loop of cord around neck.. will this create any problem ?

Not usually. it's still early and baby will move around hence loop may move away.

The cord can get wrapped and unwrapped on its own. In the womb it does not cause a problem. At the time of delivery a single loose loop is not a cause for concern. Multiple loops may impede the baby from coming thru. The doctor will decide closer to date and will surely give a trial of labor.