TTC/When to Test?

Hi ladies, so my husband and I are on our first cycle of TTC and I am 4 days away from my projected period. I am so impatient and keep telling myself to wait until the day of my period (hopefully it doesn’t come) to test... but could I test on Saturday and get accurate results? Also is it possible to get a negative two days beforehand and then end up with a positive? I am just so excited and anxious to find out... any advice or tips or anything would be greatly appreciated for our journey.🥰