Ok So I Have The Nexplanon Implant In My Arm

ok so i have the nexplanon implant in my arm it is due in September , that is when my 3 years are up ,..... well i haven't had a period since i have gotten this implant me and my fiancé have been having unprotected sex since we are wishing for a child in the future , but all of a sudden i got discharge last week which i haven't had since i have gotten the nexplanon so i was thinking that i was ovulating so now since then yesterday morning i woke up to use the restroom and found that i was bleeding through my viginal area so i had thought that the birth control is already wearing out since it is time to take it out in a few months , so i put a tampon in but when i took it out after 8 hours i wasn't bleeding at all , so i took a shower and there still wasn't any blood well i played down to go to bed and all of a sudden i started bleeding again but when i bleed it isn't much it isn't even covering the whole tampon so i got another tampon and went to bed well i woke up this morning and i wasn't bleeding again so i don't know what is going on . can you help?