Am I eligible for the 72 hour visa-free policy?

I am a Romanian citizen, currently holding a short-term X2, with one single entry. I am already in China and have used the entry. I plan to visit Hong Kong and then come back to Shanghai from where I have my flight return ticket. my flights are Hong kong - Shanghai - Romania (with a 8 hour stopover in Qatar)? What will happen with my X2 type then? Thanks