At what point should you shop around for loans?

[Eddie Gonnella]

At what point should you shop around for loans? When you are getting pre-approved, or later when you are ready to put in an offer? 

I just spoke with one lender and might have them run my credit to get pre-approved. Is this the time to also have a few others do the same? Or should I wait until I'm closer to purchasing? I'm probably 2 months from purchasing. 

Thanks!