Last time i had sex was in feb, period seemed normal for the past months, however this month i am a week late. is there still chances of pregnancy?

Not if negative: Home pregnancy tests are very accurate. They are the same tests used in a doctors office. They can detect a pregnancy 7-10 days after conception. If you doubt the result you can repeat it in 1-2 days. If you were pregnant the hormone level would rise enough for detection. After this much time clearly you are not pregnant. See your doctor for irregular periods.