After a week of protected Intercourse, I started with a light bleeding which was thin in consistency and the flow was less and the color is red, but yesterday at night I experienced a bit heavy flow and bleeded much, today is the third day and I'm still bleeding but not so heavy, I have been having irregular periods and the flow varies, I'm very concerned that if it's a implantation bleeding or it's just my periods, I didn't had cramps and back pain, the bleeding has little bit of clots but not very clotted, am I pregnant? Please doctor guide me into this , what is happening with me ?