Pregant on implant

Hey i was just wondering if anyone had ever had the same as me im currently on the implant but think im pregnant but i dont know how when like i said im on the implant i can feel like i am having fluttering in my stomach and the person i had intercourse with wasnt fully erect and it.only last like a minute so could i actually be pregnant it says that i should of been due on like last week but i only came off on the 12th of april am i reading my chart wrong aswell hope anyone can help thabk you