Help confused..

Has anyone ever has implantation bleeding and if so what was it like??? I have been pregnant 5 times 3 babies. However I have never experienced implantation bleeding before. I mc about 4 weeks ago and everything was normal with it. I am supposed to start in 3 days. We had unprotected sex a few time (not trying to convince but not stopping it) yesterday I felt like I might start and never didn, but this morning I wiped and there was blood so I figured I started put in a tampon and went on my way got off work did some running around got home figured it would be full and changed it. There was only brown blood on the tip (spotting) so it has been 8 hrs since the spotting.. With my last mc I started spotting when I ovulated which I did on the on the 27th and the 28th... I'm just not sure what is going on.