M.P.
I urge you to focus on the child that you have while you wait for pregnancy to happen. My daughter is now pregnant and she has only one fallopian tube. It only takes one egg. You might look up fertility issues on the Internet. A mom on this site said her doctor said to have intercourse for 10 days of the month, starting around the time of ovulation. There are mathematical ways to determine when ovulation is apt to happen. Many women don't feel ovulation but yet they get pregnant. My advice to you is relax! Stress and tension can stop ovulation.
You've written several posts about this which makes it seem to me that you're very focused on getting pregnant. Remember that there is much more to life then giving birth. You are very fortunate to have one little one. Perhaps that is all that you should have. I do believe that everything happens for a purpose and if I were you I would accept that one may be enough and focus on making yourself happy with the one you already have. If you're meant to have another it will happen. And.....it's more apt to happen if you're relaxed and enjoying your life.
Above all, your little one deserves to have as much attention as you have to give her. You have the time now. Enjoy what you have knowing that she is precious and loves you. You do make a difference in her life. Take satisfaction in that and let go of what you don't have.