Travelling to US before China

Hello everyone!

My boyfriend and I are going visit for a student exchange. We heard our visas have been approved and we'll be receiving them back next week. We have the opportunity to go to Seattle, US with friends just before we go to PRC. Is there any issue with travelling outside of your country before this visit.

We'll be staying in PRC for 6 months with a student X.

Any help is much appreciated!

Lis :)