Looking for a pager company in MD

My wife is pregnant and I was thinking that I might need to be contacted urgently (both during the pregnancy and when the child is around). Using my cell phone isn’t a great option since it is somewhat large and doesn’t work well inside my building.

That got me thinking about pagers. Does anybody know of a good company that supplies pagers in the Maryland area (near DC). I’m looking for the basic one-way numeric pager and not wanting to spend more than $7-8 per month.

Thanks in advance.