TTC, Discharge??

Kourtnie • 18 years old 👑 expecting my 1st in October 2017 🤰💕
Okay so we just started TTC. I started my period July 18th, lasted until yesterday mid day. I had spotting but for the most part, my period ended. Which isn't normal. Lastnight we had sex, and today, I have very very stringy brown discharge.. Very little also. What could be the cause of this?