Pregnant on the Rod!

Hey girls!! So I’m on the contraceptive implant rod thing 😂🤦🏼‍♀️ I’ve had it in since August. My periods have been on and off, so one week period for 6 days and the day it finishes exactly a week later it’ll start e.g finishes Thursday, following Thursday my period starts. Anyway, so now I thought I got my period but it’s just been really light spotting for Tuesday to now Sunday. So barely noticeable. I’m a really anxious person about anything but I’ve been to the doctors often and I don’t think I am pregnant. I’m just curious if anyone has fallen pregnant on the rod what the symptoms were or what happened ....

Thanks