Hi, first I will say that I am not a physician.
The good news is that it sounds like your condition is not caused by heart problems. That does not mean that you heart/chest is not effected by something else that could be going on medically. If you want to press the issue then meet with your physician again. They work for you. There is a heart monitor that you can wear discretely for a few days that will track the changes in its rhythm. The device records the information and is read at your doctors office.At the end of the test it is up to you to keep a diary of your diet, in take of caffeine or other stimulants, stress level and activity minute by minute. Then they can track a cause and effect. I am not sure how much this costs or when it is considered covered by insurance, but its worth a try.
If you find that there is a pattern that is related to your menstrural cycle, you should insist that your doctor (gyno) run checks on your hormone levels. Thyroid condititions can cause palpitations. The other thing to think about is dehydration or water retention related to your period. It is relatively normal for women's brains to swell a little because of water retention it sometimes causes headaches and occasionally, can cause the body to go "crazy" (ie pms) and shoot off adrenaline, or other "stress hormones" for no reason. Also, you have a one year old, talk to your gynecologist about hormone changes after birth or breast feeding.
It could be anxiety, but it is better to check everything and have an answer, so you know that you can cross off the possibility of heart attack off of your list during these attacks. If you know what I mean. It will save you the $800 bill at the emergency room once a month. You can tell yourself, "ok, I am going to live, I need to breathe and eat something." that always works for me. I also, call my mom or my husband until the feeling passes, so I dont run to the people in the grocery store and tell them to call an ambulance anymore. : )
just so you know, hyperventalation causes numbness and tingling in your arms and hands. It also causes tightness in your chest. You can start to feel palpitations and then, think "well thats weird" so you start thinking about it and start breathing short quick gasps then.......
I am your age, so I understand the look that you get from doctors when you are worried about your health and they think you are stressed out. But the symptoms are scary and you want them to stop occurring. Once it happens once you worry about it happening again. It is hard to accept that it is anxiety because it seems harder to control. Understand that anxiety is a natural reflex that fires when its not supposed to. You can read about the physiology here somewhere here, but essentially, your brain says "we are in trouble". You blood rushes to organs that need it most to survive, heart, lungs and brain. There are a ton of other chemical changes during panic attacks.
Ok, I have yapped enough. Can you tell I have been there? Take care.