Jen's prolactin was actually tested about a month ago, and since the RE didn't call us to discuss problems (he said he'd only call if anything was off), we're assuming it's fine. Her lining has also been checked when we were looking for follies, and it has been nice and thick. But I've encountered both research and personal accounts of people with normal prolactin levels (who are ovulating and seemingly doing everything right) having difficulty conceiving while breastfeeding and then getting pregnant very quickly after ultimately weaning. It seems like maybe some people are just more sensitive to low levels or fluctuations (or something else that I just don't know enough about). This is why I was especially interested in the mention of the HCG booster or progesterone in one article I read--it's a way to work around the problem without weaning.
So if we don't want to wean, why are we asking? Well, we do have a limited number of vials left of this donor, so there will come a point when we either have to take some time off to save vials until we do wean, or switch bodies. But we don't know if that's necessary, and that's what we're trying to figure out.
As far as spacing goes, yes, I know it's not the most important thing in the world. But our hope was for our kids to be about two years apart. If it ends up being more like 2.5, 3, 10...fine. But our hope was as close to two as possible. Each cycle takes us farther from that at this point, which is not the end of the world at all, but you can't blame us for wanting to keep trying, right?
(Jen edited and contributed thoughts to this post. Therefore it counts as her NaBloPoMo post of the day.)