Bleeding after sex, not period or first time, is it serious?

Patient: I had unprotected sex one day ago, and later that evening I noticed I was bleeding. This is not my first time having sex and this blood is darker than my normal menstrual bleeding. The blood has become thicker and I’m afraid this could be something serious. I wasn’t expecting my period since it’s the 15 of January and I ended my last one on the 10th. My periods tend to be irregular, and long. Does this mean I’m pregnant? The sex didn’t seem to be anymore rough than normal, so I didn’t think that it would be because of damage. What does this mean? Im afraid to see a doctor because my parents don’t know im sexual active. Thank you for your help.

Symptoms: bleeding

Doctor: