I took lipid profile last aug 14.. is it still valid/accurate?

Test validity: Yes still valid but if you have made changes in diet exercise meds etc it might have changed numbers so be worth rechecking.

Yes: Yes unless your diet has drastically changed in last 6 weeks

Lipid checks.: The frequency of testing would really depend on your clinical situation. If you're managing your lipids by diet, exercise and weight loss then it may be acceptable to check your numbers every three months to see how you're doing. If you're on medication as well, and your dose is stable and numbers are acceptable, then checking once or twice a year may be acceptable.