I am not using any form of contraceptive, and have been having unprotected sex using the "pull put method", or withdrawal method. I have always been a regular month to month (regular levels of discharge),most of the time with elevated PMS symtoms indicating my upcoming period. However this month I was did not experience any PMS symtoms and started my period on the 28th day from my last period, only difference is that for the first time ever my period has only lasted 1 day. This was followed by a yellowish/brownish discharge, but no bleeding. Please advice me if this is a possibility of pregnancy, and if so, when would be the best time to take a reliable home test?