Can this be implantation bleeding?

I had sex June 9th. June 10 i got my period like i was supposed to and it lasted heavily for 5 days. Lately i have been REALLY STRESSED about being pregnant. I ovulated june 24-25. Then I got light bleeding June 27-28. Besides from this light bleeding Ive had sore breasts (Ive been messing with them for a week to check if im pregnant). After those 2 Ive had NO pregnancy symptoms. I took a ept blue dye +/- pregnancy test. and it came out negative. ten minutes and it was still a negative. Hour later i looked again and it had become a VERY faint positive. On June 27-28 was this light bleeding due to stress or implantation bleeding?