I had unprotected sex on December 4th and my period was due around the week of December 13th. I began to have extremely tender breasts for two straight weeks. Then on the week of December 26th I received some light spotting. The next day I had heavy darkish red bleeding (I went through a pad and a tampon) and the next day my flow had become very very light almost to the point where I thought my period had stopped. The last day some brown blood that had returned even after I thought my period was over. I felt a little nausea on the last day and my breasts were a little bit tender. As of now I tried to have sex yesterday and I felt an incredible amount of pain. As well as I had some bright red bleeding right after sex with painful cramps that lasted for the rest of the night. I woke up and now my vulva feels irritated even when I try to put underwear on. So my question is, was the blood I experienced the week of my period actually implantation bleeding? Also why am I feeling pain during sex and why did I bleed? This was the first time I've bleed after sex.