Mongolia-Beijing-Spain for a spanish citizen

I'm a citizen from Spain and I have been doing a trip around Mongolia. I'm gonna take a flight from UlaanBataar to Beijing and in less than 3 days I'm gonna take another flight with another company to Spain.
Is there a problem that my final destination is my local country? I mean my trip Mongolia-China-Spain does not repeat any country so it is considered as transit and is corrected to get that exception of 72hours?

Thank you very much on advance for your reply :)