I had intercourse on jan end.. then on feb i had periods on time.. but this month it delayed 6 days. is it a cause of pregency...

Maybe: If you are late for your period you can test for pregnancy now. The over-the-counter tests are usually pretty accurate starting 12-14 days after conception. Usually conception occurs when you ovulate, which is generally 14 days prior to menstruation. What you may not realize is that many women have the occasional irregular cycle, and ovulate later than expected, so their period will come late too.