White liquid doesn't always come out. Women can have white looking liquid at various times of their cycle, and if they're sexually aroused or have orgasmed. This doesn't always happen - sometimes it's just a slight wetness. Try not to listen to anything you;ve heard from friends or anything like that because at your age most of the information going around is wrong or misinformed.
Anything you want to know, don't hesitate to mail me and I'll help you out.
White discharge during sex is due to the secretion of vaginal secretions. Regarding continuous menstrual cycles, it can be due to menometrorrhagia. Various factors causing it are endometriosis, ectopic pregnancy, hormone imbalance,endometrial hyperplasia, polyps, use of IUD’s and depo shots, sexually transmitted diseases, PCOS and benign and malignant pathologies of the uterus.
You need to consult a gynecologist and start with the treatment of menometrorrhagia.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.