I have a trend of starting my period on the 23rd of every month, but I’m three days late for my period as of currently. I am a sexually active individual, but I always use protection. My boyfriend even goes as far as pulling out despite wearing a condom and then we check for holes in it after. We haven’t spotted any, of course. I’ve been showing signs of my period arriving, e.g. spotting, slight cramping, acne, but still no luck. I’m not typically late on my period, but could it be because I received ketamine treatment for my cancer five days before my impending period?