Usually a doctor will tell you that you need more than one month's worth to be sure the pill is effective.
And protecting yourself with a condom will protect you from STDs, which the pill does not do.
Please don't economize on this, and either go to your OB-GYN and get a prescription for more months' worth of pills, or go to the drug store and buy condoms. Better yet, both.
Disease and pregnancy are a lot more expensive and difficult than a doctor's appointment or a visit to the pharmacist's.