Doctors are not infallible, after all they are only human and can make mistakes. If you feel like the problem was not addressed correctly or with the seriousness it should then by all means go to your own doctor and I suggest you go ahead and see your Ob-Gyn ASAP. This is important not ignore things like this when your pregnant.
I would definitely go in and see your doctor in the morning. Please do not just ignore this. I do not want you to worry but this can be something serious that needs attention for you and your baby.
Let us know how it goes and we are here for you and will answer any questions you may have and support you any way we can:)
Congrats on being pregnant. I remember describing things as pops. Especially in my back. Now this was in your chest but our body starts to stretch and move preparing and making room for this baby and preparing for the birth. I have a feeling that's what it was.
Symptoms of a heart attack for women are different than men. It can be upset stomach, bad neck pain, dizziness, I have heard a feeling of deep dread right before. If you aren't happy with the ER results have this followed up.
I really think it's being so far a long and your body preparing itself. I would also call your gyn and ask them what they think. Try not to worry, time to rest and get ready...
All the best to you and your baby.