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If your periods are regular of 28 days and if you have unprotected intercourse
in first week then the chances of pregnancy
are less & with PCOD
the periods are many a times irregular .If you have taken Unwanted-72 as advised on the pack then the chances of pregnancy are even lesser.Presently you can just wait & if you are worried & miss period then get a urine pregnancy test done to rule out pregnancy.As for the stomach ache if it is lower abdominal pain
you may get period bleeding due to the pill you took.