Starting to worry something is wrong... 😕

My husband and i have been ttc for 8 months... We are both young(early twenties) and the last two months i have used opks and we had sex before during and after ovulation. I still have not gotten a positive pregnancy test... The only thing i could see that could be causing us not to get pregnant is that we use spit for lube... Anyone have any pointers?  Feeling worried that something bigger is wrong...