I just happened to post something similar on the NOD October forum. It seems like my fertile days are also announcing themselves with a sticky string with some brown mixed in.
I've come up with the following explanation for myself. The cervix opens up a bit during fertile days; otherwise, the swimmers couldn't get through. So it's also possible that a little bit of old blood and some mucus come out. It's Thursday today, and I expect my ovulation around Saturday/Sunday, so it's very possible that my LH tests will start to rise in the next few days.
But your body can also just react strangely for a couple of months because maybe your cycle needs to get back on track? That's about it for my practical part.
It's so brave of you to take that big, courageous step. And it's great to hear that it worked out well for you!
I hope your wish comes true very soon, because I know from my own long wait for a child that it can never go fast enough.