am i pregnant?

Hello. So, exactly a week ago i slept with this guy. We are pretty serious, well i thought, but he never told me what we were. Anyways, he finished inside me and i thought it was ok because im on the nexplannon, i have been on it since may. Well, recently ive been spotting, getting headaches, tire out easily, my sense of smell is stronger, and ive been really gassy. I looked these up and theyre connected to pregnancy but idk. I havent taken a test yet either because i wanna do it at a more accurate time, and i read one week after a late period is the best, but with my birth controly last period was november. Can someone please give me advice??