been on birth control for a year & something weird is happening

hey there, i’m 18 & ive been on the implant for almost a year & i got the implant march 5,2019 but ever since that i’ve never gotten my period & now it’s 11/30/20 ive been having blood spotting on my panties & it doesn’t smell or look like period blood. i don’t know what it is & i don’t know if it’s a mini period or what. but idk if this matters but my sex life is active, usually have sex once - twice every week or every other week, i do let my man cum inside me but i’m thinking what if it’s a miscarriage? but recently i’ve been getting really bad headaches but no cramping, no upset stomach. but i feel like the headache is also because i don’t eat but i have no idea what this blood spotting is. AND it only happens at night, i only bleed when i’m laying down to go to bed. throughout the day there absolutely no sort of blood so idk. but please help.