Brown-ish discharge with a dot of Pink

Patient: I am a 20 year old female, and have been sexually active for approximately 7 months. Yesterday (11/30/14) I had sex with my boyfriend. After I got home that night, I noticed brown-ish water like discharge. I am aware that my period should be happening approximately 1 1/2 weeks from now, but I put in a tampon late last night – about 11pm. Today (12/1/14) I took the tampon out, and found brown, a tad clumpy, liquid, and I saw a pinkish color on the tampon as well. I took a pregnancy test, and it came back negative. I am on birth control called Chateal and I take it religiously. Is this an early sign of pregnancy?

Symptoms: Brownish Discharge, with minute amount of Pink

Doctor: Birth-control pills are unlikely to fail if taken in recommended cycles under expert supervision. A home pregnancy kit m ay be used to test urine for presence of some hormones that comes in urine only in pregnancy. Sometimes repeat pregnancy tests at serial interval may be necessary to confirm or negate pregnancy.Vaginal discharge is common in some infections of the vagina. Vaginitis, as it is called, may caused by bacteria, protozoa or fungi. Some infections cause profuse discharge through vagina, often foul smelling ones. This may be very embarrassing. Sometimes, tinge of blood, also a sign of advanced infection, or menstrual blood may impart pinkish color to the discharge of vaginitis. Treatment may be offered in the form of vaginal pellets, or especially for the virgins, oral medicines. These kill the disease causing microbes. Vaginal fluid may also be examined under the microscope to identify the possible offenders (pathogens). Please see your family physician for diagnosis and treatment of your condition.