Please read and help!

Kerry
Hey ladies, I've already scoured Google and got no luck. My partner lives 230 miles away but was home for 3 days this weekend. We had sex twice, he didn't pull out. I am on the pill and take it religiously every morning at 10 (give or take half an hour) The Friday he came home was the 7th day after my pill break for my period so I had been taking the pill again for a week on the first night we had sex. Today, 1 1/2 days later I had brown discharge like what you get at the end of a period. 
I have two daughters and delivered my second prematurely, at my check up jut before I gave birth they said my cervix had a small abrasion which was causing my bleeding (and contractions). 
Do you think that the discharge ive just had could be from my cervix or could it be implantation bleeding?