I haven't had my menstrual cycle yet this month, should i be concerned that i haven't had it yet? i haven't had sex.

Monitor your cycles: Keep a menstrual diary and tract the start and end of your cycles. Your mediciations may be interferring with your cycle.

Periods can vary: I would suggest you try not to worry about a late period. Since you have not had sex, the late period could be due to stress, lack of good nutrition, poor sleep, or many other causes. Some women do have variable periods without anything at all wrong with them. If you continue to be late, please see a physician to properly diagnose the problem, if any.