Thanks for reaching out and good question! We would suggest trying at the very first sign of ovulation (or within 12-18 hours of that first sign). Then use the next syringe with another sample 18 to 24 hours after the first.
You want to make sure you try to conceive prior to ovulation occurring. It takes time for the sperm to swim through your body all the way up to where the egg is released. When the egg is released from your Fallopian tube you want those little swimmers already there and waiting. I'd also encourage you to check out our blog post Timing It Right for some helpful tips.
We are crossing fingers for you and here to support you so feel free to email us at firstname.lastname@example.org with any questions.