implantation bleeding or no.

Hello everyone. I have a serious question to anyone who can help or may know... Okay ive been trying to conceive for a year now after i had a still birth last feb, and my body has been very difficult since then. My partner and I have had sex during my ovulation period of my cycle, and again this past friday after ovulation just to be sure. So tracking my expected implantation date its schedule for the 29th, but i woke up this morning on the 28th bleeding. It started off light wearing only a panty liner, but as the day went on the bleeding has gotten heavier and im wearing a pad to bed. My period isnt due for another 6 days. Could this be implantation of a baby, or just an early period? Oh yeah i did cramp slightly but now im just bleeding. any suggestions? im worried.