Does Preseed work

Does preseed work? I am 27 and my hubby is 28. We are TTC since 5 momths and no luck. I use ovaulation kits.  We have a 2 year old son. I got pregnany after 3
months with my first baby. I have used concieve plus for 2 months and still no luck. I have preseed. Does it work only if you the applicators and put it in your cervix or does it still work if you use how much you need from the tube?