I'm 3 days late! I need advice.

Melinda
​Ahhhh okay so me and my husband are trying to get pregnant, my period was supposed to start on the 27th it's always here on that day every month! But since we are trying have been taking test and even my test yestersay showed negative. Should I wait until I'm a week late until I call the doctor? Or what should I do? I was reading online it could take up to two weeks to get a positive? Has this happened to anyone else? Help please. (: