Hi I Have An Irregular Menstruation Cycle And Miss My

Hi I have an irregular menstruation cycle and miss my periods frequently. I recently had sex for the first time and it was protected by all means. I have missed my period for the month and 6 days after my first intercourse I saw reddish brown secretions coming out of my vagina, the vaginal opening hurts when touched and I had mild cramps too. Am i pregnant?