Tips on TTC

Any tips on how to get pregnant fast? Currently entering my 7th cycle for number 2. I got pregnant on my 7th cycle with my first so hoping the same will happen again. I had a chemical pregnancy on our 2nd cycle trying and have had no luck since. I’m finding it harder to pin point the right days to have sex this time around, my ovulation was always day 15 when trying for my first, now it’s anywhere from day 15-19. My husband is burnt out by the end if I end up ovulating later then day 15 and we end up stopping and losing our chance. I currently take vitamin b6 and vitamin c along with a prenatal. We also use pre seed or conception plus. I track ovulation with bbt and take opks. Anything else I can do? Should I not have sex until I get my positive opk? I’ve been starting on day 12 and trying to do every other day