Has anyone's loan officer ever given them a really low estimate on PMI, and then it turns out to be much higher?

We are working with a loan officer who has been great so far, but I have trust issues... He calculated our PMI as less than $30/month on a mortgage of 278,000 ($61,000 down payment, or 18%).

AND we don't really have a credit score. Well, my husband has a decently high score but it only came from opening up a store credit card that he didn't realize was a credit card and has never used. Therefore he has no credit history and the loan officer said they would basically act as if we just have no score.

One thing I've learned is that if something sounds too good to be true, it usually is. And I'd always heard PMI is way more than that.

What do you guys think - can I trust the estimate from our officer?