I haven't had my period in 3 months. is that bad?

GYN F/U: If you have just started having periods - irregularity is not uncommon. If you are a woman who regularly has periods- it warrants discussion with your gynecologist to determine the cause.

Hard to say: You did not post any information on your past pattern of menses, other medical history or other related symptoms. If you had a hysterectomy or ablation this would be expected. Without such information I could only advise you to contact your OBGYN. If appropriate they may decide to trigger a cycle with medications.