understanding my cycle 🤔

please I never haven't understood my cycle .... the only thing I know is my period last 5 days and the month of July I had my period July 3 first day and spotting stop like the 7th or 8th . I was on the shot so I finally had my normal period.

kind of ignorant myself on this also would like to know my fertility which I still don't Understand😂😂🤔🤔🤔😩😩😩😩😩😩 I don't want to get pregnant at the moment. I'm on the pill 😰