I have nexplanon and my boyfriend does not use a condom. I have had nexplanon for roughly a year and a half. I do have irregular periods. Last night at about 4pm I began have very painful cramps and this continued till about 1am, I have previously had some brown spotting and notice old looking blood when I have been to the toilet and wiped. I have looked online for what it could be, going from it being a strange period because of nexplanon, to it being implantation or some horrid condition. Please give me some advice.