While Loading Groceries In My Car About 2 Hours Ago,

While loading groceries in my car about 2 hours ago, I had the strangest feeling in my abdomen and chest, just a weird weak feeling like I've never felt before. Felt like it started in my stomach and moved up over my check. Then my head felt very dizzy and I thought I might be about to pass out. I held on to the car and took some deep breaths and it went away in about 30 seconds. It concerned me that I was having a heart attack or stroke possibly. Felt fine after I got home, and no other symptoms tonight. Could this be a panic attack? I've been under a lot of stress at work recently.