How To Treat Irregular Periods?

hi i had an abortiona year ago i went on birth control and recently stopped taking it. i also quit smoking marijuana a few days before my period. it is now irregular i normally last for 5 days its lasted for seven the last 3 days have been brown clotted blood which is normally only on the last day. i have been trying to get pregnant this month and don't know whats going on i need help.