Ok, what is up with those lower (very low) abdominal twinges? I wouldn't necessarily say they are painful, but they certainly don't feel comfortable. It's been happening a few times a day for the last week or so. It feels like the baby is doing something down there and I haven't the slightest clue to what it could be. Is this something I should be feeling at 7 months? I don't see my doc until next week.

Probably just muscle stretching :-)
*Could* be Braxton Hicks...your uterus practicing for the big day. It's hard to tell all those apart...even more so with your first. But I'd say, at this stage of the game, it's simple muscle stretching. And yeah, sometimes it can come and go, be kind of rhythmic..not one long stretch. Yeah, very confusing.
Don't sweat it. Unless it gets rather intense and frequent.