Bit of background info

I’m 16

On the pill for 1 month now

On my period week

Been on my period for 4 days now but supposed to have two days left but haven’t bleed today

Ok so. I was chilling and was checking my panties every few hours for any sign on period and noticed really weird discharge. It is like white, clear, and kinda discolored at the same time. It’s also realllyyy sticky. It smells like vinegar too. Don’t know if that last bit of info was nessesary but figured it might help. Does anyone know what this is? Is it a sign of pregnancy? Is it a sign of infection? Please help