Trying to get pregnant

Hello everyone I been on birth control off and on for some years now but recently I been on the implant which cause some problems I been the implant since April 27th 2018 every since me and my partner have been trying to get pregnant I got my period may 18th till the 22nd tryna figure out when would I ovulate I really want kids Previously over the years I been pregnant on birth control and had miscarriages I been tracking my ovulation with no luck is too early to test for positive ovulation? I want to believe the app which says my fertile window start tomorrow