I've been on birth control for 5 months now and have had unprotected sex with my boyfriend many times while on it. I've never experienced any problems, or scares, before. My period is unpredictable and I am never quite sure when I will be getting it. Last month it lasted for about 3 weeks so I don't know if I should be expecting it any time soon. Wednesday, April 6, was the last time my boyfriend and I had unprotected sex. Thursday, April 7, I stayed home sick from school with a sore throat and headache. I was supposed to start Bactrim that day, and was given one in the morning by my mom. Later in the day I realized that I had taken the antibiotic and that it decreases the effectiveness of birth control. I have not taken the antibiotic since, in fear that I could become pregnant. I am currently still sick with a cough, which is causing me abdominal pain so I am unsure if it is pain from the cough, or stomach pains that could mean pregnancy? Also, I started bleeding lightly the other day but sometimes it is a little heavier than spotting. I am unsure about all of this and was wondering if anyone could give me some insight. I plan on taking a test this Wednesday since it will be 2 weeks after the initial unprotected sec, but I have been stressing a lot lately.
Did you find this post helpful?

User Profile
replied April 18th, 2011

Welcome to ehealthforum

After the last episode of unprotected intercouse you took the antibiotic just once as explained by you so there is no possibility of pregnancy if you have been taking the pills before that regularly.Antibiotics decrease the efficacy of birth control pills and while on them it is advised to use extra protection.
It seems that you are having your menstrual bleeding.Since you are sick kindly take the prescribed medications as advised and if you have intercourse in between use the protection.
Relax yourself as you did not have intercourse while on taking antibiotic.If any symptoms worsen kindly see a Physician for evaluation.

Take Care!

Did you find this post helpful?
Must Read
Birth control is helpful in preventing pregnancy. Need to know more about birth control? Start here to learn more about popular methods of birth control....
You have many birth control options. Each works differently. What are the choices and what should you consider in order to help you make your decision? ...
Each method of birth control comes with risks to your health. What are the general problems you could encounter?...
DISCLAIMER: "Ask a Doctor" questions are answered by certified physicians and other medical professionals. For more information about experts participating in the "Ask a Doctor" Network, please visit our medical experts page. You may also visit our Am I Pregnant , for moderated patient to patient support and information.

The information provided on eHealth Forum is designed to improve, not replace, the relationship between a patient and his/her own physician. Personal consultation(s) with a qualified medical professional is the proper means for diagnosing any medical condition.