Hi,
I have SPD which is really painful, especially at night. I find that the only thing that helps me is by moving as little as possible - definitely no lifting anything. Also, keeping your legs together, sitting down to get dressed, swinging round to get in and out of the car and bed etc etc. Try to avoid going up and down stairs, no hoovering, sweeping, mowing the lawn are all things I was told to avoid by the physio. Rocking on a gym ball can help. If I take it easy it's not so painful at night, but sometimes it seems to flare up for no apparent reason.
The physio gave me the above advice and basically told me I'd have to grin and bare it until baby arrives and then it should go - i hope they're more helpful for you!