can i do PAP smear if I got weird vaginal discharge?

It looks like period blood but the discharge is brownish (like dry out blood/old blood) and the flow is low. Usually happens in my period days coz after i have this discharge i wont get any period coming after.

It worries me that something wrong with my body. Coz most of the time i get normal period bleeding except certain months i get these brownish discharge. I'm never had sex before so I'm thinking if PAP smears able to find out what's wrong?