Probably really silly but advice needed

I'm so paranoid, me and my SO have sex a lot and my contraceptive implant runs out in a few months. My body does not react well to hormones and rejects most of them. AF was two days late and finally came after a terrible week of constantly feeling sick, however it's really light unlike usual and sorry to be crude but it's also gooey which is so strange! What's happening to me and what should I do?