Do i get my Period late when travelling?

Gigi

I was supposed to have my period between 18 and 22 January, on 18 January i have travelled to a near country.

today it is 26 January and nothing yet.

I had 2 pregnancy test and it was negative.

Does travelling affect my period and if it is late, how many days the delay could be?

Shall i take primolut if doubting pregnancy so that i can stop it?