Late Period

My nexplanon expired in March. I haven't gotten around to getting it replaced yet, but my boyfriend and I have been using condoms with a few mishaps. My period was supposed to come on the 18 of May. I have been getting a few pregnancy symptoms, but they can also be in my head Im sure. Today is the 25 and I am cramping ob my left lower abdomen and very lightly spotting (only when I wipe and its also a mix of clear discharge with light streaks of blood). Is my period just way off? Could I just have ovulated really really late and this implantation? Thank you.