Answers please!!!!!!!!!

Me and my boyfriend are trying to have a baby so i need yall help. I started my period May 26,2015 I'm trying to see when is the best time for us to have sex because last month I started my period April 20th, 2015 and I ended on May 4th,2015 we had sex on my ovulation day but nothing, but a period that came 2days early. I'm really trying to see is it normal that it came that early? And when would b the best day or days this month?