I'm not a midwife either (though I do have plans to become one once my children are no longer nursing every day). My first DD was totally "engaged" from about 26 weeks on. I managed to waddle around feeling like she was about to fall out of me for 11 more weeks. It was not fun, but even after my water broke unexpectedly, my cervix did not dilate beyond 3 cm. So no, I don't think you need to worry about that. Now, then, if you are having other problems, too, you might want to work on taking better care of yourself and reducing the stress in your life. But the baby being low in and of itself is not something to worry about. If I were you, I'd do a lot of squatting and pelvic tilts, and not spend much time on my feet or sitting in a reclined position.
ETA: I do have a tilted uterus, never thought there was any sort of connection, though. I carried my 2nd DD much higher. I'd take shortness of breath over having a thimble-sized bladder any day!