I have no idea what I'm doing. Help?

Kaylene • Down to earth and open minded. Love animals and my husband.
My husband I were just married on October 18th of this year. We've known each other almost six years, but we've only been a couple for nearly four and a half. We just knew that we were right for each other, and so our relationship moved along rather quickly, but it never felt uncomfortable. After a long engagement, we're finally married. However, we've been trying to conceive for almost four years. I've gotten pregnant once, which ended in a devastating miscarriage. It has taken me a long time to come to terms with it, but I understand that sometimes things just happen. Now my problem is that I don't know why I haven't had like, twelve children by now. Seriously, my husband and I only used condoms and birth control for the first few months of our relationship, so what's going on here. I've spoken with my doctor about possible fertility problems and all she tells me is "keep trying". It's very frustrating. Does anyone out there have advice on methods to try? Are there any herbal supplements I should be taking? Ive been taking Vitex, but maybe I should try something else...?