Birth control

So i had a baby a year ago and i didn't get on birth control until 3 months after she was born i got on the pill for the first 3 months and i stopped because i gained ALOT weight i was also getting my period none stop so i went to my doctor and decided to switch to nexplanon. The problem here is that i been on my period ever since i mean it will stop for 2 or maybe even 3 days but during that time im still spoting and i go back to what i would think is my period. Has anyone ever had something similar happen?