Part of it may be that during pregnancy your ligaments get looser, maybe that is playing a part in the increased problems.

If you can find a very good PT or even a body worker of some sort {Alexander, feldenkrais, hellerwork etc} they may be able to get you back on track. Or at the very least, they might help to alleviate any postural issues that might be a factor.
I'd make sure they are knowledgeable about the pregnancy aspect.