Best day to test post ovulation

Might have missed my peak day (super upset about that). I was taking Clear Blue Advanced Digital and from Saturday until last night (4 days) had a high result every time. Once I got my first high result I started testing twice daily. We had sex Saturday and Monday. Our research suggested every other day was best but as soon as I got a peak result we planned on having sex at that time as well. Well my peak never came. Tested this morning and got a low result. I'm supposed to start my period on Christmas eve and would really really love to give my husband some good news as a gift. What is the best day to test post ovulation that might not give me as much disappointment. We have been trying for almost a year.