Sorry new to this TTC!!

Melissa • 33 yrs old I have two wonderful boys and one beautiful step daughter. I`m a nurse and going to school to become a PA.
I'm not used to keeping track of my periods or take an ovulation test. I started my period lightly on the fifth and heavy on the sixth I'm finished yesterday and had sex. When is the best time to take an ovulation test? Please help! Thanks! Oh and does anybody have endometriosis and having a hard time to conceive?