An extra penny for your thoughts. Mailing a letter costs a little more, with the price of a first-class stamp rising to 42 cents Monday.

People who planned ahead and bought Forever stamps for 41 cents each can still use them without extra postage.

New Forever stamps also went up to 42 cents Monday. But buyers may want to stock up anyway, looking ahead to next May when prices are expected to be adjusted again.

The cost to mail a post card also goes up, to 27 cents. Certified mail costs a nickel more, at $2.70. Priority and express mail also are getting more expensive.