I love teaching prenatal exercise and working with moms & pregnant women, but I'm not a big fan of pregnancy itself. I have to say, though, that while I was pg with my first, I had this sudden realization that this was just the beginning of things I wouldn't be able to control. Just wait until you have a picky eater or a 2 year old who is going through the "NoooOOOOooo!" stage. LOL... just when you THINK you know how to be an effective parent LOL

Pregnancy is a HUGE reminder that you'll be living your life for more than just you... and I think it's a hard transition sometimes, but well worth it!
I'm at 27 weeks now, and I feel like my belly is going to explode some days... I have varicose veins, lots of round ligament pain, occasional heartburn, and I'm exhausted this time around (this is my 2nd pregnancy)... yep, I'm a big whiner when I'm pregnant.
It helps to put the time in perspective. 2 months seems like an eternity, but think of what you were doing 2 months ago... seems like it just happened, right? Once your baby is born, you'll lament that the time goes by so fast -- they grow out of the baby stage way to fast!
As for the changes in your body, since you've been an exerciser, your body will get right back into the groove after your pregnancy, even though you're taking a break now. Muscles do have memory!! In the meantime, do you think that your body could handle a water workout? At the YMCA where I work, we have a therapy pool, and I've seen pregnant women just walking laps to relieve the pressure. Treading water or doing laps with a kickboard (if regular kicks help, try a side stroke or frog kick)migh help, too.
I had my son in Feb. 2000... I'd lost all 43 (yes, gulp, 43) lbs. by July of that same year by exercising 4-6 times a week (stroller classes, prenatal/postpartum aerobics, and usually a jog on the weekend) and nursing. I didn't diet, and I felt like I was stronger and in better shape by the end of that 1st summer than I had been when I first got pregnant.
Hang in there

Susan