Welcome beckyw1982, sounds like you're a perfect candidate for the new pregnancy exercise thread here . Maybe you'll find someone there to help you, or pick up some ideas of stuff to do at home.
The buggies thing really is a minefield. We got a Jane 3 wheeler travel system, the travel system aspect was great as DD basically slept for the 1st 4-5 months in the pram/carrycot part, saving us from getting a moses basket, and the carseat you can clip onto the chassis was invaluable for transferring her without waking. It was also comfortable to use for us and her.
BUT on the downside it's pretty huge, for example we couldn't fit it into the lift to get to my MIL's house without dismantling the whole thing and no way would I even try taking it on the train. Also, we live somewhere where we have to go everywhere by car and so it wasn't actually used that much for long shopping trips or walks to park or whatever. After about 18 months we really used it very little as DD likes to walk and we never have to go that far. So it's lucky really that no.2 will be coming to justify all the £££s we spent on it.
You really have to think about your lifestyle and how you'll be using it, and that's not easy if you're a 1st timer. I must admit I chose ours mainly on the basis of how cool it looked and a fantasy of long country walks with baby, which never happened of course.
This time I'm on the lookout for something light, cheap and that you can fold up/unfold with one hand, as I never solved the puzzle of what you're meant to do with your baby when you're doing this, I mean hold it in your teeth or something? Anyone have the answer?