The definition of being a virgin, is someone who has not engaged in sexual intercourse with another human being and/or someone who is sexually inexperienced ~ so it sounds like you are still a virgin :)
The bleeding after masturbation could be due to a couple of things; you may have ruptured your hymen ( the membrane at the opening of the vaginal canal) which usually causes spotting or bleeding which can last from 1 to 3 days, or you could be experiencing irregular periods which could either happen too close together or too far apart from your normal period... I suggest a few things, stop masturbating for awhile and see if the bleeding stops, and/or go to a clinic and speak with a doctor about your concerns and history of bleeding ~ personally I would do both. At 18 years old you are an adult and able to seek medical advice without your parents consent...
Take Care, and good luck!