Hi doc...I have a reg. Period and it always come every 19 of the month...and it last 4 days I'm on a 28-32 cycle....this Sept 19-22 got my period on 23 we had sex and I take my 1st pill of Diane am I safe for pregnancy?

1st pill of Diane? Depends on what happened. If "1st pill of Diane" means the first pill in a new package, but the woman had just finished her last month's package of Diane (or other similar birth control pills), then she is protected already, because she taking her pills properly and is not just now starting birth control pills for the "first time." If starting for the "first time," effectiveness is less certain.