my tailbone is killing me !?

Lea
Hi lady's ! 
I'm almost 27 weeks now and My tailbone and hips been killing me after sitting down or laying in bed ! Last night it got so bad that when I tried to get out of bed and tried to walk, I feel down and had a really hard time getting up again. It's almost like my legs get stiff and I'm not able to move past a point or put any pressure on my legs ! It's aweful and even though I'm usually not the person to, i have to scream out loud and even cry last night ! 
Ive always been really active and also still work out, so I doubt that's the problem. 
Is anybody else experiencing it as bad as me or do you have any tips on how to avoid or make it go away ?