Why arent we getting pregnant?

Okay, so I know you ladies arent a bunch of doctors and that. I'm just curious to see if anyone could offer information or advice? I have 3 kids 2 with 1 man, and 1 with another. My hubby has 3 with 1 woman. We've been married over a year now and have been trying that whole year with no luck....I'd like to say were both pretty fertile so why is this taking so long for both of us? I've been using ovulation tests.