First, you may get pregnant out of the box, you might not. I've been pregnant 3 times, my first was not planned, my third was while I was nursing and on the pill (that resulted in a miscarriage) and my middle pregnancy, 2nd child, was actively conceived, but not until my 4th cycle of trying. That's relatively quick. I have friends who've gotten knocked up every time as soon as they decide to start trying, and I have friends who tried to conceive for years before getting pregnant.
You should start to change your dietary habits now. I wouldn't recommend crash dieting to lose or anything. Get your diet in check, eat at a caloric deficit and see what happens. You can add calories back in once you become pregnant. As for strengthening your back, things like planks and supermans will help with core strength. If you want to lift heavy, most of the big compound movements engage the core for balance, and specifically the deadlift will strengthen your back. Just be sure to learn proper form before attempting to go too heavy.
Edited by: JENMC14 at: 2/6/2013 (16:07)
I am 5'4".
Starting Weight (4.6.11) 164.6
First Goal 130 - Reached September 2011
Currently maintaining under 120 and working on changing my mental image of myself!
| current weight: 136.0