How much notice does a landlord need to give on a month-to-month lease?

Question Details:

I signed a year lease. After the end of that year it was to be a month-to-monthlease. Yesterday I received a notice in the mail stating that my month-to-month is due to expire on the 31st 3 weeks from now) and I have until the 26th to sign a new lease at the increased rate or move out on the 31st. Also she stated that at anytime before the 26th if I have not signed a new lease she can revoke that offer and I have to be out on the 31st. I am concerned because I just don't think this is right, as well as what would have happened if I never received this notice via the regular postal service? Important Notice