Advice Ladies?!

Okay so, My last period started on July 29th and finished on August 3rd. Since then I haven't had a period. I was supposed to be finishing my period today but it never came at all earlier in the week. At first I thought it was stress or maybe even weight gain but I'm not stressed anymore and my weight has been constant. Should I go see a doctor? And if I do what should I expect or prepare for?