Heart beat in my stomach &chest..1 is fast & the other is slower.i been nervous cause i been thinking i'm pregnant. if i walk long i feel pressure at ?

Anxiety and stress: if you were pregnant, you should have different symptoms than 'feeling a heart beat in your stomach'. Fetal heart beats can be heard, generally by the second trimester, by outside devices placed on lower stomach. If you haven't had a physical recently, you should get one. If indicated, your doctor can order an abdominal US to clarify any swelling or source of inflammation in your abdomen.