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Lake Elsinore, CA
A 20-year-old female asked:

I took cephalexin, 4 pills a day (for 10 days). i am 2 days late for my period, and i've never had sex before. is it the antibiotics?

1 doctor answer1 doctor weighed in
Dr. Brian Nguyen
Obstetrics and Gynecology 13 years experience
Not the Antibiotics: They only antibiotic known to affect the metabolism of your hormones is rifampin. Cephalexin is totally safe. Sometimes periods can be a few days late, just give it time.If you wait more than a week and don't get a period, only then would i worry.
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Related questions

A 36-year-old male asked:
On day 6 of two types of antibiotics for cellulitis which is improving. Some blood clotting in my urine today. Antibiotics causing this? Trimethoprim 2-800mg twice daily, and cephalexin 2-500mg twice daily.
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See DR: This is an unusual combination of antibiotics. "Cellulitis"? Where? Fever? Due to strep? Pain on urinating? Some strep infections may cause glomerulon... Read More
Created for people with ongoing healthcare needs but benefits everyone.
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A 20-year-old female asked:
I started taking cephalexin antibiotic four days ago. I started having red bloody mucus in my stool. I have mild abdominal cramps. What do I do?
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See your MD: Your condition needs medical attention. It could be related to the antibiotics (or not). You need stool studies including stool c. Difficile toxin, f... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 19-year-old female asked:
I am on birth control (Yazmin) and i toke Keflex. I had unprottected sex (without ejaculation) 2 days after i finished the antibiotic. Im pregnant?
Dr. Liesa Harte
Family Medicine 31 years experience
Not necessarily. : It is possible, but you should just do a pregnancy test if you miss your period.
Created for people with ongoing healthcare needs but benefits everyone.
A 18-year-old female asked:
Does the antibiotic cephalexin make birth control pills less effective?
Dr. Robert Kwok
Pediatrics 35 years experience
No: The current thinking is that except for rifampin, other commonly-used antibiotics (such as cephalexin and many others) do not alter the effectiveness ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
A 29-year-old male asked:
I have a leg infection , right side near calf from a large turf burn playing football that Im taking antibiotics cephalexin 500mgx2for. And it is healing but I only have a couple pills left. Should I request more? I still see it drain?
Dr. Donald Colantino
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It's best to have a physician examine and advise you. It is.not unusual to have to stay on antibiotics for 2 weeks to treat cellulitis. Cephalexin is ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
Last updated Jun 24, 2014

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