I usually carry it in my back pant pocket or the front pocket of the fleece I'm wearing.

I wonder if my cell phone is too close to my pregnant belly.

Did you change where you put you cell phone after becoming pregnant?

ETA: I found this article. I need to do a search for the actual study this article is based off of.
http://www.nydailynews.com/life-style/health/yale-study-cellphone-pregnancy-bad-babies-health-article-1.1039527