Retroverted uterus is no big deal, and I have 2 healthy babies to show for it! I did a ton of research on it back in the day and did read at some point that there might be a teensy advantage to conceiving if you're on top, as the anatomy and gravity work a little better that way. But to be honest, given the other issues you've dealt with are all way more cumbersome than a flipped uterus.
Your uterus will flip out of the pelvis by week 14 or so and be like any other pregnant uterus, so no worries about the birth, either. Then after giving birth, it will flip right back! Don't give this one another minute of worry.
Good luck on your TTC journey!