4 days late...🤞🏻

I am almost 31 and my husband and I have been trying on and off for a year now. My periods are very regular and only ever differ by a day (29-30 days). As of today my period is 4 days late. It was supposed to come on Saturday. I have taken 4 urine tests on Friday, Saturday, Monday, and this morning all of which were negative 😒. Could it possibly still be too early to test? Or am I just wishful thinking? I don’t want to keep spending money on tests this month for them to just keep showing me negative results. Has this happened to anyone else? Any advice please!