pulsing from chest to throat.

For the past few weeks I've noticed a weird pulsing/throbbing in my throat when I physically strain myself. This evening I picked up my 5 year old son in a "baby position", once I put him down and stood up straight, I start to feel this pulsing coming from the middle of my chest up to my throat...its almost like I can't breathe correctly. I have to calm myself and it goes away...it lasts for no longer than 30 seconds. It's isn't painful but uncomfortable. I'm a very anxious person, and I'm convinced there's something wrong with my heart at this point... any doctors have an opinion?