Asalaamu alaykum,
I apologise for the nature of this message but I am getting really worried and have tried to contact some sister mods as well.
I had to stop fasting due to my menses cycle which I know is allowed. However, I am really worried that I might accidentally be missing a day when I am actually tahir due to me not being sure. I get really irregular periods and there is no consistency really. I also recently read about something called istihaadah and I have no idea how to tell which is which although I have read the signs to distinguish. They really aren't very helpful when you get irregular periods to be honest.
I woke up today just a few minutes before Fajr and I assumed my period had ended due to not emitting anything over night. I didn't check much further than this but I made an intention, did the ghusl and fasted today (today being the 6th of Jan). I then proceeded to fast and pray today although occasionally I was wondering if I did the right thing by simply making an assumption and not checking further by using a cloth or something. I was praying Maqrib when I then emitted more blood but even whilst praying I just thought this was normal discharge and kept on praying. It was only later I realised it was a small amount of blood which I think might be istihaadah?? but I don't know because normally for me, the last few days of my cycle, I do get irregular bleeding which seems to be similar to what istihaadah seems to be :S But I always just assume it to be part of my menses cycle so I'm not familiar with this.
I'm worried about today, whether the fast was valid. Obviously I wouldn't worry so much if it was not valid due to menses because that wouldn't affect my kaffarah to the best of my knowledge insha Allah but just in general, I am really confused. I don't know if I should make another ghusl or what or if I'm meant to restart my kaffarah because I'm wondering if the yesterday (5th of Jan) when I got really small traces/irregular bleeding, that was istihaadah as well.
Can anyone please help me on this matter

I only began my period on the 2nd of Jan and to be honest, if I hadn't read up on this istihaadah thing, I would have just assumed day 4/5 and small irregular bleeding was just part of my period and nothing else but now I'm getting really confused. I normally wait till day 7 and then make a ghusl because bleeding normally comes to an end on day 6 but I've always been told it was best to wait a night and half a day or so to make sure completely than rush to make ghusl but because I am worried I might not be fasting on a day I am tahir, I am rushing my ghusl in case my menses has ended.