Hi, I Am A 20yr Old Woman Who Has Been

Hi, i am a 20yr old woman who has been on the pill Levlen Ed for about 4 years. I recently stopped the pill in April and since then have only had one period (straight after stopping). I am wanting to get back on the pill but have not had my period in 4 months. Do I need to wait until I have my next period before starting again?
Thanks.