i had an extreme version of this in pg #1 and am having it again this time. i actually have what's called separated pubis symphysis, where your pubic bones really separate too far and create MASSIVE pain. here are some suggestions:
if you can, sleep in a recliner. i know, sucky, but you won't regret it if the pain gets bad at night. if you have to sleep in a flat bed on your side, make sure that you keep your legs together at all times. if you have to move your legs, move them together. you may find it helps if you just act as if your legs are paralyzed and move them with your hands. maybe your pain isn't as extreme as mine, but i have to do that or it's excruciating.
don't cross your legs - it messes with the whole area and creates more strain.
don't lift ANYHTING heavy. it WILL strain your pubic bone and your hips. i don't know why, but it does.
when you walk, try to take smaller steps. if you're dealing with a lot of relaxin (that is how it starts, then the pressure from the growing baby makes it worse), you want to keep your pubic bones as close together as possible.
get a maternity girdle. i have one on order and i can't wait to get it. i'm gonna try to find the link of where i got mine. you can just google "maternity google" and get lots of great sites. look for one that has a vaginal support AND a hip support. the regular maternity belts will help somewhat, but not where it really counts.
if you end up having extreme problems with it, be PERSISTENT with your practitioner. if you are in danger of separating your pubis symphysis there are positions during labor that you CANNOT DO. they didn't diagnose me until after the fact, and had me pushing my baby out on my back in stirrups. the absolute WORST way to labor/birth if you have a separated pubis symphysis. i was in danger of literally cracking in half, and didn't know it. it can be really serious if you don't get someone to take you REALLY seriously.
*HUG* i hope it's not as bad as mine...take it as easy as you possibly can. good luck, mama!!!