Double the tracking didn't give me twins, it just happened! Honestly, just get a basic checkup done, start prenatals, and don't stress too much or you'll be exhausted before the babies even arrive.
First rule: stop treating baby-making like a high school board exam! Just take your folic acid, enjoy the 'process' with your husband, and throw those crazy ovulation strips out of the window for a bit.
Now that my little one is a toddler running around, I look back and realize how much I overstressed about ovulation dates. Just focus on a healthy diet, daily walks, and keeping your mind happy.