For months, economists have warned that historically low mortgage rates couldn’t last forever. It looks like that promised rate increase may finally be starting to materialize. Interest rates for 30-year fixed-rate mortgages increased to 5.31% from 5.04% the previous week, marking the third straight week of rate increases, and the highest rate since August 2009. The higher rates reflect continued improvement in the economy and the end of a federal program that kept mortgage rates artificially low. Nobody expects rates to skyrocket, but most economists do expect a gradual upward drift in rates. The Mortgage Bankers Association expects fixed rates to hit 5.8% by the end of this year and 6.3% by the end of next year. So what does all this mean for you? If you’ve been waiting to purchase a home until home prices fall further, an increase in rates could wipe out your gains. A $300,000 mortgage taken today would cost $190 less than the same mortgage taken at the end of 2011. That’s a difference of almost $70,000 over the life of the loan. So unless you expect home prices in your area to tank in the next two years, it may be time to start shopping. As for refinancers, what have you been waiting for? If the rate you’re paying is more than a point above current rates, and you plan on staying in your home for the next few years, it’s time to call your mortgage broker. Even if your mortgage is slightly underwater and your loan is owned by Fannie Mae or Freddie Mac, you can still refinance under the Home Affordability Refinance Program, which allows refinancing with loans worth up to 125% of the home’s value. You may have already missed out on the record-setting sub-5% rates we’ve seen over the past year, but today’s rates are still pretty low by historic standards. Follow MONEY on Twitter at http://twitter.com/money.