HCG Injection and Implantation Bleeding

About 13 days ago, I received an HcG Injection when my follicle was at 2.6mm.  As instructed, I had intercourse with my husband the following morning and the morning after in hopes of conceiving.  I had been feeling ill and bloated, and experienced heavier clear and whitish discharge until 11 days after.  The night of the 11th day, there was some brownish discharge followed by light pink watery discharge (one or two times red but not heavy).  This was a few days earlier than my expected period.  Could this be implantation bleeding or could the HcG injection have been causing these symptoms and may have triggered an early period.  I did not take a home pregnancy test as I am not expecting my period for a few days.  Alos, within the last 2 days, with the light bleeding, I have been urinating quite frequently. Thank you for your help.