I have had the same thing! Everytime I get out of bed, get up from the couch, walk after standing/sitting for a long period of time; I have a ton of pain in my pelvic area. I went in to see the doctor hoping they could provide me with a solution; but nope she just told me to go buy a belly band that supports baby from the bottom relieving all/most of the pressure. It almost feels like someone is standing behind me and holding her up =)
I am wearing it for the first time today, so I can let you know how it goes it you want.
This is often normal. It's associated with round ligament pain caused by your growing baby & uterus stretching the ligaments. We're all made up differently. I've had pain in the same areas. To make you feel more comfortable, check with your OB next visit or call your nurse for a quick answer. :) I'm 22 weeks this week, just a week behind you.
I have had a lot of pain in that area and it is completely normal as far as I know.
I've had some moments of lower pain during my pregnancy. Nothing that hangs around too long, though. There's all kinds of stretching and growing going on in there, so weird pains are normal as long as they come and go. I think if you've had the same pain for days on end I'd get checked out, though.