I had my last cycle July 18th. A couple days ago I experienced a light pink discharge. Is this implantation bleeding and could I be pregnant?

Implantation bleeding is not as common as you may think. Women rarely experience it. If you have had unprotected sex recently, you could very well be pregnant, but as it is getting close to your next cycle, it could also be that. The only way to know for sure is to wait until the period is actually missed ( at least a week past due) and test. Good luck! I hope the outcome is as you wish.