There are symptoms. If you get chest pain, a rapid or irregular heartbeat, shortness of breath (whether at rest or during an activity that doesn't normally cause you to be short of breath), fluid retention in the ankles, legs and feet or fatigue you don't think is normal with a cold, then call your doctor or go to an emergency department.
Keep in mind that millions of people get colds every year, and most don't get myocarditis. It's possible, for sure, but you'll know what to look for now. :)
Feel better soon!