I had unprotected sex on July 16. About two weeks later (roughly July 27-30) I had what seemed to be a normal period. Then on August 22nd I started bleeding again. I started out like a normal period, but then change to light either brownish or light pink in color. It appears to be implantation bleeding, I have no clots and I only bleed semi normal on the first day. I have not had sex since July 16th. Could I be pregnant? I've also been experiencing some light cramping, mood swings, enhanced sense of smell, cravings, headaches, peeing more frequent, tiredness, although some insomnia, slight constipation, and some breast tenderness.