Traveling and delayed period?

So I went to Vegas on December 11-14th. My last period was November 16th . and I have not gotten my period for this month yet. I went to the emergency room on December 22nd and and found out I had strep throat and they did a pregnancy test then and it was negative . so my question is. Should I test again or could my period be delayed from traveling? Also me being sick has never thrown off my periods . just let me know what you ladies think. Thanks!