I had (somewhat) unprotected sex on my ovulation day (November 13th), but my partner did not ejaculate, as we put a condom on fairly soon into the process. My period should not be due until November 28th, but I started it at 12:30 am on the 19th. At first, it was a dark brown, thick consistency, but it quickly became more of a blood-red. It has been much lighter than my usual periods, but still has had some obvious clotting and has been enough for me to need to use around 3 regular tampons a day. It has been fairly consistent up until around 6pm tonight (November 21st), when I noticed it has stopped. (Usually my periods last 5 days). Do you think this is simply an early period, or could it be implantation spotting due to pre-***? I have had no pain, nor have I had any other symptoms that I've read come with implantation spotting (nausea, breast tenderness, cramping, bloating, etc). My periods are usually pain-free. I'm just very alarmed that it arrived 9 days early.
Could it be stress? In the past week, I've been under a lot of stress due to school (I am a college nursing student), and on Friday night (the day before it started), I was informed I would have to put the cat I've had since childhood down. Would this have any effect on my menstrual cycle? Do you think it could be heavy implantation bleeding? If so, when is the soonest I can take a pregnancy test? Please be specific in your answers.