Hi L.,
I know nothing of birth control because I have never been on any kind. I just wanted to give you encouragement to not give up. My husband and I went a whole year trying to conceive before we finally did and like I said, I never was on birth control. My cousin had her first baby almost 4 years ago and it was another 3 years before she was able to conceive again. As you can see from your other responses every woman reacts differently with birth control. I guess what I am trying to say is when or if it is time for you to have another child, you will. Stress doesn't help the matter either. I don't want to minimize your desire to have another child, I understand that urge and need. I would just suggest stay busy with your two children, enjoy every moment, and if you are blessed with another child, what a wonderful blessing. If you never have another child, you still have two wonderful blessings.
Saying a prayer for you...
Beth