I'm diagnosed with PCOS so I'm on Clomid. Saw my gynecologist on 17/07 and she said I would be ovulating around 19-20/07. This tuesday I took an early pregnancy test, it was negative. Later that day I started bleeding so I was a little bit down (first time I reacted to the medication and an egg grew so I wasn't hoping for too much). The bleeding was very light and immediately stopped. I only had one tampon with spotting. Haven't bled since.

Could this be implantation bleeding. Should I take another test and when?