9 days late. Need some advice.

I need some advice, my period was supposed to start on 10/16. I have taken 4 hpt and all of them are negitive:( My period is normal, starting on or about the same day every month. What should I do wait,go to the doctors? My husband and I have been TTC for a little over one year, so we don't want to get too excited, just in case. Does anyone have some advice for me?