I had unprotected sex in the beginning of January. Two weeks after, I got my period but it didn't last as long as usual. I am due for a period in around a week following a 28 day cycle, however for the past 8 months my period has been pretty irregular. I have only had 4-5 periods since June but before that I was on a 28 day cycle. Now I have been spotting for the past couple days. I've been stressing about this and googling it and now I'm wondering, could this be implantation bleeding?