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Pull out method is the most risky method and carries high chances of pregnancy as precum can lead to conception.Chances of conception are more during the ovulation period if precum was released.
It is difficult to comment without an examination and information is just based on the history provided.
If the periods do not start then consider doing a urine test for pregnancy determination.You can also get a Blood hcg test done which gives accurate results.Kindly visit a Gynaecologist for evaluation.
Take care!