Thanks for posting your query at DoctorSpring.com
With post coital bleeding and irregular bleeding between cycles, what you need is a through gynecological exam.
It should entail an internal exam with a speculum, a Pap smear and a pelvic transvaginal ultrasound scan.
With a clear smear in 2012, yes you can wait until a month.
What other alternative would you have, other than waiting for your OB - GYN's next opening ?
All the best
Please feel free to discuss further.