Hi, Im Not Sure If I Should Call My Ob

hi, im not sure if i should call my ob or not. I have been bleeding a brown vaginal discharge for almost 3 weeks now. I have had irregular periods in the past and recently had some large ovarian cysts which i think stalled my period ( I had not had a period in 2 months) but then had a regular one and a week before my next one was supposed to start I started the brown vaginal bleeding and it hasn't stopped for almost 3 weeks. what should i do? (i am not on birth control and we are trying to get pregnant)