I'm currently 33 weeks pregnant with twins and for the past few weeks have noticed a swelling at the bottom of my bump. It's sensitive and if you press it leaves an indent. The Dr said that it's just water retention. The very bottom bit looks horrible, like little blisters of water (this may be the indents of stretch marks from my first pregnancy). If I wear sports leggings which are a bit tighter, the little blisters go. Has anybody else experienced this?