AF due Feb 25th

Hi! I'm 35 years old, 36 in a few weeks. I have a 28 day cycle and AF is due 2/25. I had a chemical pregnancy last cycle and lost it at 5 weeks 2 days and we are jumping right back in. I bought ovulation test strips, but I have no clue what the heck I'm doing. I've been off birth control for 10.5 years, but only started "trying" a year ago and REALLY started trying (tracking and sex on peak days) in September.