It can be, you must visit a doctor, its not necessary that you are having heart problem but you must go for a check up.We can't avoid any accident by closing our eyes,we can avoid it by being aware of it. OK?
Second thing which I feel is that it could be happening due to weakness, I hope you must be taking some good multivitamins and if its not so, then you must take it. Because as time passes and female get older, different deficiencies occur in their body which must be cured.
I have a prescription for left arm pain which you are telling, I had it once and doctor told me to take simply two Disprin tablets dissolved in half glass of water. It helps to make your blood thin and flow easily.Sometimes thickening of blood causes stress and aches of body.

Make it sure to see the doctor as soon as possible,
Get well soon!

It very well could be heart problems. This is nothing to mess around with and you SHOULD NOT HESITAaTE going to seek medical attention. Not one more minute. Go NOW and get it checked out. If not for yourself than for your loved ones around you. If you love them than go NOW and get it taken care of.

U need to undergo a stress test.consult ur doctor to see a cardiologist.
it can be angina pectoris, unstable form.
keep nitroglycerine tabs with u , u might need them

I am just a few years older than you. I went through a similar thing a few months ago. My doctor's response when I said I had been waiting to see if it got worse was, "ARE YOU NUTS? You should have been in here the first time it happened!" In other words, CALL YOUR DOCTOR NOW! Nothing was wrong with me but it needs to be addressed in a serious nature. Don't wait for it to get worse. Good luck and best wishes.

Most people hear of heart attack symptoms with pain down their left arm. In women, this can be pain in their RIGHT arm or no pain in the arm at all. In fact, women are likely to be fatigued and short of breath, not sleeping well. Many women NEVER have chest pains at all. But, make no mistake about it, there can still be a serious prognosis. Another big symptom is that of anxiety.

You say that you've an anxiety disorder already so the anxiety of that can be confused with the anxiety caused by a cardiac condition. I'm not there, but this certainly warrants a trip to your doc, because it's a well-known fact that women and men present differently with heart disease.