How often do you have sex when ttc??

Haley • I am married to the man of my dreams and we have two beautiful little girls (8 and 2) and another baby girl due in May!
I have heard that you should have sex every other day when it's fertility time in order for the sperm count to be at its highest but I've also heard you can do it every day and it really doesn't matter at all! 
Just curious, really. Last month my husband and I BD almost every day and I got a BFN :( this month were trying to do it every other day in hopes that it gets us a BFP