My wife is 20 years old.We got married 2 months ago.we have sex on July 24,July31 and August 12.In this time we don't want baby.I used condom all the three times,but at the first day condom breaks,and so to avoid pregnancy my wife take contraceptive pill at the day of first sex.But,we were worried about the pregnancy.My wife test 2 times by pregnancy tester,but there was no evidence of pregnancy.But,my wife's belly become fat,sometimes she feels some pregnancy symptoms such as vomitting,nausea,left breast pain.It is also the side effect of the pill,I know that.But,I can't figure out whether she is pregnant or not.She feels so much shy to go to doctor.And it should include that her mense occurred at the right time 2 August and remain for 4-5 days.My question is,Is my wife is pregnant or Why those symptoms are shown?

If your wife were pregnant, and I am not saying that she is, it would be too early for her to have any pregnancy symptoms. Her belly wouldn't be "fat" because of pregnancy yet. That doesn't happen until a woman is about 3 - 4 months pregnant.

Right now you have to wait to see if she gets her next period as expected. It is too early to test yet.