About to ask dumb questions

So guys I have some questions:

1) when you don’t wear a panty liner and just wear your underwear should your discharge leave a yellow mark ? Like if its dried up ?

2) how much discharge is too much discharge?

3) when should you be worried that something is wrong ?

I ask because idk I’ve been freaking myself out lately about my discharge. It doesn’t smell or anything, it’s just more than usual and sometimes it has a faint yellow tint to it. Idk if it’s cause I had sex Saturday and my vagina is still cleaning itself or is it something else because right now I’m going through my fertile days. I just need like a crash course on when I should go seek help or am I just being paranoid. Oh and sex wasn’t with a random person was with my boyfriend so idk. I’ve been checking my area way too often.