Just thought that I might add .. that *67 is used to block caller ID from reflecting on the phone that is called in to. So .. it appears that your H and this gal are trying to hide the fact that your H is calling her?
If you want to catch your husband .. or at least firm up your suspicions, you will need to appear that you are not "watching" at all. You mentioned that your H made a comment about feeling like an 8 year old. Well (IMO) if you want to "catch" him, make it look like you are not paying attention ..at all.
You got a lot of great advice here .. in regards to how to find out (for sure) if your H is cheating.
Now that you have those strong suspicions what are YOU going to do? Have you had the chance to purchase Michele's book yet? There are many threads on this BB that have (somewhat) similar situations. Hopefully you can take the time to read up and get some ideas as to what you can do .. ?