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Date of last update: 10/14/2017.

Forum Name: Gynecology

Question: Not sure if I am pregnant?

 smiley0329 - Tue Sep 06, 2005 8:49 am

Well last month I didn't get a period. I am on orthro-tricylen lo and have been for about 2 years. I continued on to the next pack of pill and still no period. I took a pregnancy test after 1 day late it was negative I then took one 1 week after still negative then 2 weeks after still negative. Is there still any chance I might be pregnant? I always take my pill around the same time except on the weekends I take it alittle later in the day. Please tell me there is no chance of pregnancy :(
 Dr. Tamer Fouad - Tue Jan 10, 2006 12:31 pm

User avatar Hello,
Ortho Tri-Cyclen is a combined phasic contraceptive pill that contains norgestimate/ethinyl estradiol: 0.18 mg/35 mcg; 0.215 mg/35 mcg; 0.25 mg/35.

With perfect use, only 0.1 percent of women become pregnant within the first year of using a combination oral contraceptive pill.[1]

The most sure method to exclude pregnancy using a pregnancy test. The highest possible screening sensitivity for an hCG-based pregnancy test conducted on the first day of a missed period is 90 percent, as 10 percent of women may not have implanted yet.[2] It was estimated that the highest possible screening sensitivity of a home pregnancy test by one week after the first day of the missed period is 97 percent.

1. Trussell J. Contraceptive efficacy. In: Hatcher RA. Contraceptive technology. 17th ed. rev. New York: Ardent Media, 1998:779-99.
2. Allen J. Wilcox; Donna Day Baird; David Dunson; Ruth McChesney; Clarice R. Weinberg. Natural Limits of Pregnancy Testing in Relation to the Expected Menstrual Period. JAMA. 2001;286:1759-1761.

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