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Birth control pills start being effective after about 3-4 weeks of use. Use of other medications can hamper their effectiveness and any unprotected intercourse at the time of first pill pack use or while using any other medications, or at time of switch over of contraceptive methods can put you at risk of pregnancy. The delay in periods could suggest possibility of pregnancy. The symptoms (felling tired, headaches, abdominal cramps, bloating, increased frequency of urination, pink discharge) too are suggestive of pregnancy. You should consider visiting your gynecologist/doctor for thorough examination and blood HCG test to confirm/rule out pregnancy.
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