Testing truths

Hi everyone! I’m new here and we have just started our TTC journey - I’m 39 and my husband is 50 so we know it may not be the easiest one.. my question is - how accurate is a test ( even though the box says 98% 1 day before missed period ) before you’ve missed your period? I got anxious and took one this morning and it’s negative but it’s the day before my period is due. Should I just be calm and wait as there might still be some hope? Thanks for any advise!!