I took mine out last week at about 15 weeks - mainly because people kept commenting on it poking through my top! I've always loved my piercing, but love it more now as DH and me get to stroke my growing belly with no interference. It's also less of a hassle when applying moisturiser - in my opinion anyway. On the other hand my twin sister used a plastic bar right the way through her pregnancy with no problems.
With regards to your last question, mine has already started to close x