7.2 is a little low for pH but chlorine is more effective at lower pHs. Still, the most harm it will do is cause swimmers' eyes to burn a little. Raising it a little to 7.3 to 7.6 isn't a bad idea. I'd add 1/4 box of Borax, then test pH 12-24 hours later.

If you smell chlorine, you are still metabolizing something. It might be a few leaves and bugs in the skimmer, or it might be something a little more serious--but only proper testing will tell.