Cycle Days

I’m may be a little too old not to understand the number of days Im on my cycle.

Back ground: when i first started it was 2 days and id be here and gone the next day. In my high-school years it moved to 3 days and it’d be gone with no “residue” of having to wear a panty liner. Towards my junior/senior year it went to 4 day. Its be super light the end of the 3rd day and gone the 4th but the day after id have to wear a panty liner because things still cane out(not “blood).

Now Im 22. It sitting around 3/4 days. But its never really gone until 3 days after the 4th day of my cycle (which I say is the end of my cycle). There no blood. Just what i call “residue”. Do I incorporate that into my cycle or no. I tried to explain to my girlfriend that im off my period but im not actually “off” bc she was trying to have sex. Because i was “off” but still had this left over crap.