Ovulating but not conceiving

Ive seen our local obgyn and ran some tests and confirmed nothings wrong with my husbands semen. Confirmed levels are normal and that I do ovulate. Ive been tracking my ovulation and still not conceiving. I use preseed on and off to see if it’ll help us but no. Ive never been on birth control. We do have a 2 year old who we conceived within 2 cycles. So we’re wondering why this time around is really hard ☹️

I need advice. We’ve been ttc for 17 months now.