Jetlagged or pregnant?

Jasmine
Hey ladies :)
Have any of you had jetlag/ international travel interfere with your cycle?  
My partner and I have been ttc for 6 months now. Last Thursday we left for a US holiday (from Australia) . I was due to get my period on Sunday/ Monday but it never showed. I've had cramping on and off since Sunday, and quite painful and noticeably fuller boobs. 
I don't usually get boob stuff at period time, but I am holding off testing because I have had late periods before that have come to nothing and it really gets me down, but the boob thing is giving me a desperate glimmer of hope...