Hubby and I sure did enjoy "trying."
After a while, when it wasn't working, we knew it was unlikely to happen. (We already knew why before trying.) If you are trying for more than three years, it is time to get medical help to see if there is any particular reason you're not having babies. But worrying about it hurts the chances.
If it's not three years yet, just enjoy the sheer delight in "trying." (Often! Why not? lol) From what I gather, once the babies start coming, there is a lot less time to "try" and "try" is just too much fun in itself.