Brown Spotting/ discharge. To continue?

Hi - I am on medication of Emersa 2MG since last 24 days post my Endomitiosys surgery. I started the medication from 14'th March. On, 22'nd March I had my period (Usual two days pain, and 4 days bleed and 2 days light spotting with the end). Before this Menace, last one was on 10'th February (I have irregular cycle). From, 9'th April I started to observe some spotting which eventually turned out to more like brown discharge and gradually stops on 15'th April. Today, i.e. on 19'th April I again observed brown spotting. What is the reason? Is it normal to have such prolonged AUB with Emersa? If so, till when I should expect this spotting to continue? Little scared , please help. PS: I have done HPT [most recent 14'th April]and Beta HSG (<1.4) [most recent 1'st April] in recent times, all came negative though. Also, Last intercourse 58 Days ago. Blood tests were done on : 28'th March and 1'st April. HPT (Urine) were done on: 18'th,19'th,22'nd March, 5'th April and 14'th April.