Period changes

I been using glow for three months still haven't conceived been trying for 11 months now .My period keeps coming on different days each month.😐it's came in the 12 then the 9 then this month on the 3 😟so I have sex on fertile days. 😇waiting a miracle I quit drinking and caffeine . I exercise more and even drink green tea as well as raspberry leaf tea and ginger tea.